The hostilities of the Asia- Pacific war ended over 80 years ago. It was a war that by most estimates took more than 30 million Asian lives, the vast majority of whom were neither combatants nor Japanese. We have considered the currents of history that brought us to the doorsteps of war, over the threshold into war’s carnage, until its end which was possibly inevitable even from its beginning. Was it inevitable? Some historians answer, “yes,” but there are always choices. It is just that you might not like any of the choices available. 

By the 1930s it was clear that Japan viewed its role as the leader of the Asia-Pacific region in every aspect by which a modern, great-power nation should be seen. The slow morphing of its self-understanding was traced in the post Japan Apart. It was not as simple as Japan understanding itself to be superior in terms of civilization, military strength, institutional stability, and a host of other measures – it was now a matter of destiny. Japan’s self-assigned role in the modern era was to be the leader, guardian and protector of Asian nations against the incursions of western colonialism that had left its mark through all reaches of the Asia-Pacific region. To their thinking, only they had risen above the grasp of western powers. They were possessed of the destiny to assume the role of leadership of a greater Asian prosperity sphere: an oriental Monroe Doctrine.

The previous several posts have added information and insights to draw closer to uncovering why Japan would draw the United States into the already ongoing conflict in the Asia-Pacific region. Was it inevitable? Some historians answer, “yes,” but there are always choices. It is just that you might not like any of the choices available. And how the choices are viewed and evaluated are “in the eyes of the beholder.” 

By 1941 Japan was bogged down in China fighting a war it started and, despite early successes, had very little chance of winning but every chance of experiencing the endless quagmire that had always been China. The fighting was already draining Japanese national reserves, was being fueled (literally) by oil and gasoline from the U.S., and was beginning to drastically reduce the standard of living among the Japanese people on the home islands. And yet Japan started armed combat with the U.S., a battle that the leaders of Japan knew they could not win militarily. It was a war the Japanese government’s Total War Research Institute reported there was no chance of winning. Even the best minds in Japan argued against the possibility of success. But as Prime Minister Tōjō once remarked: “Occasionally, one must conjure up enough courage, close one’s eyes and leap off the veranda of the Kiyomizu Temple.” Their actions were not rational; made no sense to the Western mind. 

The presumption of irrationality is natural when considering the latent military and industrial power of the U.S.. But “counting the costs” was not the criteria employed by Japan. Their decision for war has to be seen in the light of the alternatives available to them: economic suffocation or surrender of Tokyo’s empire and imperial ambitions/destiny on the Asian mainland. The choices made by the United States have to be seen in the light of the alternative available to them at the same crossroads of history.

Japanese aggression in East Asia was the root cause of the Asia-Pacific War. Given that perhaps war was inevitable, but the road to Pearl Harbor was paved with American as well as Japanese miscalculations.

Rationality

History does not lack accounts of the irrational. Consider Winston Churchill and Britain in 1941. The British army had been driven off the continent as the last soldier evacuated from Dunkirk. By mid-1940 there was no one who could challenge Hitler’s control of Europe.

Was Churchill’s decision to fight on after Dunkirk rational? In May-June 1940 Britain had no means of effectively challenging Hitler’s on the European continent. Britain was down to its last hope: American and Soviet entry into the war. The Soviets had a non-aggression pact with Germany and the situation in Europe was not enough to bring America “off the sidelines.” The people of the United States were not interested in again being drawn into “European affairs” as they were in 1917. Only profound mistakes by Germany and Japan would change Britain’s strategic fortunes to bring the United States into the war.

A rational Winston Churchill would have explored the possibility of accepting German rule on the continent in exchange for allowing Britain to withdraw from the war and save the remains of its empire. Perhaps this was the sun beginning to set on the British Empire. Was it rational to continue the good fight? It would have been epic, heroic but ultimately foolhardy and futile. The choices were the heroic last stand, negotiate peace, or hold on until the Axis powers take irrational actions.  

In June 1941 Germany invaded the Soviet Union. In December 1941 Japan attacked Pearl Harbor. They were the seismic events that changed the tide of history. 

American naval historian Samuel Eliot Morison called Tokyo’s decision for war against the United States “a strategic imbecility.” [Quoted in Gordon Prange’s Pearl Harbor: The Verdict of History] Apart from all the reasons already noted in previous posts, the United States lay beyond Japan’s military reach. Though Japan could fight a war in East Asia and the Western Pacific, it could not threaten the American homeland. In attacking Pearl Harbor, Japan elected to fight a geographically limited war against an enemy capable of eventually waging a total war against the Japanese home islands themselves.

Dean Acheson, who in 1941 was Assistant Secretary of State for Economic Affairs, declared before Pearl Harbor that “no rational Japanese could believe that an attack on us could result in anything but disaster for his country.”³ Secretary of War Henry L. Stimson believed the Japanese, “however wicked their intentions, would have the good sense not to get involved in a war with the United States.”⁴ Admiral Isoroku Yamamoto certainly had good sense. In October 1940 he warned that to “fight the United States is like fighting the whole world.   Doubtless I shall die aboard the Nagato (his flagship). Meanwhile, Tokyo will be burnt to the ground three times.” 

Perhaps the most savage indictment is that of historians Haruo Tohmatsu and H. P. Willmott: “[N]o state or nation has ever been granted immunity from its own stupidity. But Japan’s defeat in World War II was awesome. The coalition of powers that it raised against itself, the nature of its defeat across an entire ocean, and the manner in which the war ended represented an astonishing and remarkable, if unintended, achievement on the part of Japan.” (A Gathering Darkness: The Coming of War to the Far East and the Pacific, 1921-1942, p. 1) Wilmott, a top tier historian, is noted for his acute and searing analysis.

Thucydides famously explained the desire of ancient Athens to retain its empire by declaring that “fear, honor, and interest” were among three of the strongest motives.  Japan’s decision for war has to be seen in the light of the alternatives available to them: war, economic suffocation or surrender of Tokyo’s empire and imperial ambitions/destiny on the Asian mainland. These seem to fall within Thucydides categories of the strongest of motives. Japan’s decision for war was made after months of agonizing internal debate by leaders who recognized America’s vast industrial superiority and who, in the more sober moments, suffered few illusions about Japan’s chances in a protracted war against America. Japan’s leaders did not want war with the United States, but by the fall of 1941 few saw any acceptable alternative to war and they resigned themselves to it.

The Blind Alley

All the above being true in perception, it would seem that the 20th century had seen a dynamic in which Japan was working its way deeper and deeper into labyrinth of international complexities with nations that were well familiar with the twists and turns of the morass. Japan has been isolated from the world for centuries, only emerging some 60 years prior. It entered the labyrinth with a certain presumption about its readiness for the adventure. By the end of the 1930s their undisguised military aggression had created a situation in which the survival of Japan as a great power, and of her conception of an Asian empire, did indeed hang in the balance. They had essentially walked themselves into a dead end with absolutely no allies in the region. It is like the driver who is lost, refuses to ask directions, won’t admit he can’t read a road map, and nonetheless pride moves him ahead deeper into an increasingly blind alley. Arguments of honor, humiliation and subjugation can be hoisted – and even agreed they don’t have to be rational – but it does not exonerate the choices made. Or the inability to see what Japan feared as economic subjugation was more likely the start of an economic partnership that would benefit Japan in ways it could not imagine. Consider the economic fortunes of Japan in the last 80 years.

But by the fall of 1941 the question had come to be not whether there was to be a war with the Western powers, but, given the regional and world situation, whether Japan’s leaders could imagine a more favorable time to solve Japan’s resource problems by military action. Japan’s relative naval strength would never be better than in 1941. In capital ships, Japan’s fleet was 70% of the size of the U.S. Pacific Fleet. It was more modern, more practiced, and already had established the ability to operate multiple aircraft carriers as a single, coordinated air fleet (something the U.S. did not figure out until late 1943 and early 1944). But during the course of the war, the United States built 8,812 naval vessels to Japan’s 589. In 1941 the United States produced 1,400 combat aircraft to Japan’s 3,200; 3 years later, the United States built 37,500 to Japan’s 8,300. Japanese leaders reasoned, better war now than later. While the odds were never in their favor, Japan’s chances of defeating the United States were better in 1941 than in any subsequent year.

Image credit: various photographs from Naval Aviation Museum, National World War II Museum, and US Navy Archive | Source credit: Samuel Elliot Morse quote taken from Gordon Prange’s Pearl Harbor: The Verdict of History | Tohmatsu and Wilmott quote taken from A Gathering Darkness: The Coming of War to the Far East and the Pacific, 1921-1942 | Utley quote taken from Going to War with Japan 1937-1941 | Tojo quote taken from Nobutake Ike, ed. and trans., Japan’s Decision for War: Records of the 1941 Policy Conferences. |

In the previous posts we considered the strategic and tactical plans that began to take shape in 1940 into 1941 – the Imperial Japanese Navy (IJN) war planning and the Germany-first strategy by the United States. Underneath all that, both Japan and the United States approached the coming conflict with deeply rooted presumptions about culture, race, and military capability. These assumptions shaped strategy, diplomacy, and expectations about how the war would unfold. In many cases, they proved to be serious misjudgments on both sides.

Japanese leaders believed their society possessed a unique moral cohesion derived from loyalty to the emperor and a strong collective identity. The ethos of duty, sacrifice, and endurance often summarized in terms such as seishin (spiritual fighting spirit) was thought to provide a decisive advantage in war. This belief led many Japanese officers to assume that national willpower could compensate for material disadvantages. Military training emphasized discipline, courage, and willingness to die for the state, which were viewed as traits lacking in Western societies.

At the same time, Japanese observers also believed that American society was overly individualistic, comfort-oriented, and politically divided. Because Americans valued personal prosperity and safety, Japanese planners assumed the United States might lack the resolve to sustain a long and costly war far from home. These assumptions helped support the belief that a sudden shock, such as the attack on Pearl Harbor, might move the United States to negotiate rather than fight a prolonged war.

In Japan, modern nationalism incorporated ideas that the Japanese people were a uniquely pure and spiritually superior race. As Japan’s power expanded in Asia, this belief blended with the claim that Japan was the natural leader of the region. Many Japanese leaders saw Western colonial dominance in Asia as hypocritical and believed Japan had a mission to reshape the regional order.

American perceptions of Japan were shaped by a mixture of limited knowledge, racial stereotypes, and strategic complacency. Many Americans saw Japan as a small, resource-poor nation that could not match the industrial strength of the United States.

Culturally, Americans often viewed Japanese society as rigid, authoritarian, and overly obedient, assuming that soldiers trained in such a system would lack initiative or flexibility in combat. There was also a tendency to believe that Japan relied heavily on imitation of Western technology rather than genuine innovation. American planners expected Japanese forces to fight aggressively at the outset but believed that Japanese morale and capacity would eventually collapse under sustained pressure.

In the United States, racial attitudes toward Japan were shaped by decades of exclusion laws, immigration restrictions, and popular stereotypes. Japanese people were often portrayed as inscrutable, fanatical, or technologically inferior, while Western societies were assumed to possess inherent cultural and scientific advantages. These mutual racial assumptions deepened mistrust and contributed to a climate in which both sides underestimated the capabilities of the other.

While Japanese racism was evident in its views of their Asian neighbors, the United States, not without its own parochial and racial views of the Japanese, lacked understanding of Japan’s history and culture that was considered secondary to the assumption of a general superiority of peoples of European descent. Prior to December 1941, the assumed moral high ground was proven by the widespread accounts of Japanese atrocities in Nanking, Shanghai, and other events. Besides, according to some experts, the IJA had been bogged down in China for four years; the Soviets had made quick work of them at Nomonhan and the Japanese Navy had not been engaged in battle on the high seas since 1905. How accomplished could their military be? Even after the attack at Pearl Harbor, U.S. Secretary of War Stimson, asserted that Nazi Germany must have planned the attack, apparently thinking the blitzkrieg at Pearl Harbor was beyond Japan’s military planning capabilities. Stimson must have been unaware the “sneak attack” was actually a hallmark of the Japanese military as the Russians discovered in 1904. So embedded were such convictions, widespread within the Roosevelt administration, that key policymakers were blinded  to the likely consequences of the decisions to impose what amounted to a complete trade embargo of Japan in the summer of 1941.

A Matter of Honor

By the beginning of 1941, Japan ruled over Korea and Manchuria, had conquered much of China north of the Great Wall and made inroads into central China, seized all of China’s major ports and islands in the South China Sea, and established a military presence in northern French Indochina. Japan was poised to invade resource-rich Southeast Asia, which Japanese propagandists had long and loudly proclaimed was rightfully within Japan’s sphere of influence, notwithstanding the fact that almost all of Southeast Asia lay under British, Dutch, French, and American colonial rule.

Japan had signed the Tripartite Act which the U.S. rightly understood as intended to deter the United States from going to war with Germany or Japan by raising the specter of a two-ocean war. Their signature transformed Japan from regional threat into a potential extension of Hitler’s agenda of aggression, especially with respect to the Soviet Union after the Nazi invasion of June 22, 1941. The hardliners in Washington DC correctly predicted that now Japan would turn towards Southeast Asia.

For the Japanese all things were a matter of honor and destiny. After the embargo it became a matter of necessity. Japan’s leaders were not certain that moving on Southeast Asia would cause a U.S. reaction but assumed that it would. The Roosevelt administration regarded a Japanese invasion of Southeast Asia, especially the oil-rich Dutch East Indies and tin and rubber-rich British Malaya, as strategically unacceptable. Control of Southeast Asia would weaken the British Empire and threaten India, Australia, and New Zealand allies in the war against Germany. Also, it would also afford Japan access to oil and other critical raw materials that would reduce its economic dependence on the United States, weakening the effect of other economic sanctions as controls on Japanese aggression.

While it might seem the U.S. reaction was simply an economic consideration. The more important consideration was keeping Britain in the war. It was a fundamental strategy of the United States and Britain that they could not afford to lose the raw material wealth and the sea lanes of Southeast Asia even if it meant war. Though the administration was never prepared to go to war over China, it regarded an extension of Japan’s empire into Southeast Asia as unacceptable. Thus Japan provoked a strong American response when Japanese forces occupied southern French Indochina in July 1941 as an obvious preliminary to further southward military moves. Operating out of southern French Indochina, the superior long-ranged Japanese naval bombers could provide air control of the seas around Singapore and support ground operations in Malay – both interim steps to the oil riches of Sumatra, Borneo and Java.

The United States was prepared to declare economic war on Japan as a means of deterring—or at least delaying—a Japanese advance into Southeast Asia, and that is exactly what the Roosevelt administration did in July 1941. The post The Financial Freeze details how those actions unfolded. In Going to War With Japan: 1937-1941, the author Jonathan Utley argues that the intent of the financial freeze was not to cut off all oil, but to ration it at a rate that let Japan know we control the spigot. Or as Roosevelt famously remarked it was to be like a noose around Japan’s neck which he would give it a jerk now and then to keep their attention. But by the end of August 1941, Roosevelt declined to reverse the decision. The reasons remain unclear. Perhaps he believed that a reversal would look like a retreat, or perhaps he had come to regard a Japanese advance into Southeast Asia as inevitable. 

What was intended and what eventually happened is the nature of unintended consequences.

The consequence was that as a result of the de facto embargo and in conjunction with the seizure of Japanese assets by Great Britain and the Netherlands, there was a complete suspension of Japanese economic access to the United States and the destruction of between 50 and 75 percent of Japan’s foreign trade. No nation would meekly accept this situation – certainly the U.S. would not if such had been imposed on them. And neither did the Japanese.

Image credit: various photographs from Naval Aviation Museum, National World War II Museum, and US Navy Archive | Utley quote taken from Going to War with Japan 1937-1941

From early 1941 onward, the Japanese were establishing and refining their war strategy which, as regards the U.S., which translated into a three part movement: attacking the Pacific Fleet in Pearl Harbor, establishing a defensive line across the Central Pacific, and attriting the U.S. fleet when they moved westward. Meanwhile, the United States did not want war with Japan and yet ended up in exactly the war Japan did not want: an extended war of attrition and logistics pitted against the manufacturing power of American industry and resources.

The historical record is quite clear that the Roosevelt administration was committed to a “Germany-first” strategy, stopping Hitler in Europe. Hitler’s facism was viewed as the modern plague that must be stopped lest it infect the whole world. In 1941 the U.S. was  engaged in an undeclared shooting war with Nazi submarines in the North Atlantic that was a precursor to what awaited the U.S. in the event of a declared war. In the first half of 1942, almost 600 allied merchant ships were lost to German U-boats. The Roosevelt Administration needed to keep Britain in the war with supplies and a key to that was avoiding war with Germany. The last thing Roosevelt wanted was a war in the Pacific. 

Jonathan Utley observes “No one during the fall of 1941 wanted war with Japan. The Navy preferred to concentrate on the Atlantic. The Army said it needed a few more months before it would be ready in the Philippines. Hull had made the search for peace his primary concern for months. Roosevelt could see nothing to be gained by a war with Japan. Hawks such as Acheson, Ickes, and Morgenthau argued that their strong policies would avoid war, not provoke one.”

The administration maintained military sales to China with the goal of keeping the Soviets in the fight, focused on Germany without having to worry about an eastern front attack by Japan. With military supplies delivered via the “Burma Road” the Chinese were able to continue to keep IJA troops engaged, bogged down, and thus Japan was unable to initiate any incursions into Siberia or Mongolia. This ensured that the Soviets did not have to wage a two-front war. 

But there was a limit: the U.S. administration was not willing to go to war with Japan over China. With Japan controlling all significant Chinese ports, the only two available supply routes were the Burma Road and smuggling via Hong Kong. The U.S. goal was to provide enough arms to China so as to deter or inhibit a Japanese advance into Southeast Asia.  This goal was advanced by relocating the Pacific Fleet to Pearl Harbor from their California ports, the imposition of economic sanctions, and beginning a slow build up on forces and long-range bombers in the Philippines. The administration was mistaken in their belief. The U.S. presumed realism and rationality on the part of the Japanese and failed to understand that severe sanction (i.e. the financial freeze and de facto oil embargo) would be tantamount to an act of war.

The Germany First Priority

The U.S. posture vis-a-vis Japan was complicated by a “Germany First” outlook that guided U.S. policy even before Pearl Harbor and shaped military planning and diplomacy. President Roosevelt and military planners believed that Nazi Germany posed the greatest global threat. In November 1940, Chief of Naval Operations Adm. Harold Stark recommended a defensive posture in the Pacific as regards Japan while prioritizing the defeat of Germany and Italy in Europe. He produced this recommendation in a memorandum that came to be known as “Plan Dog” which laid out U.S. options in the event of war against Germany, Japan, or both. He reviewed several possible scenarios and plans, lettering them from “A” through “D,” and ultimately recommended Plan “D.” At that time, the U.S. Navy’s phonetic alphabet for “D” was “dog”: hence the name.

U.S. leaders came to realize that the scenarios underlying the older “color-coded” war plans were based on the assumption that the United States would fight a war against a single enemy one-on-one. It was increasingly clear that these were no longer realistic assumptions. The United States was increasingly likely to face war against multiple enemies across the globe. In which case, the country would need allies, which meant Britain, Australia, New Zealand, and the Netherlands, all of whom had interests in the Southwest Pacific. 

By November 1940, France had fallen, and Britain stood alone against Nazi Germany and its Italian allies. The German bombing campaign against Britain had begun. Recognizing the consequences of a British defeat, President Franklin Roosevelt had been gradually increasing U.S. support to the United Kingdom, first through the “cash and carry” policy in September 1939, and then through the “destroyers for bases” deal in September 1940  which became the December 1940 Lend-Lease program. In Asia, meanwhile, Japan’s invasion of China continued, and in September they occupied the northern part of French Indo-China. 

Roosevelt was constrained by public opinion, which strongly opposed U.S. involvement in another major foreign war. Stark’s memorandum, therefore, came at a critical time—before the United States was formally at war, but as war was looking more and more likely. It was by no means clear what course the United States should or would follow. Admiral Stark laid out the essence of the grand strategic problem facing the United States, and he concisely crafted the best courses of action. Plan A was war with Japan only and no allies. Plan B was war with Japan only supported by British Allies. Plan C was war with the Axis allies and no allies of our own. Plan E was no stay out of the wars all together

Plan Dog was we’d be at war with Germany and Italy in support of Britain while Japan was not yet involved. Any involvement with Japan would be at the initiation of the United States.

“…our major national objectives in the immediate future might be stated as preservation of the territorial, economic, and ideological integrity of the United States, plus that of the remainder of the Western hemisphere; the prevention of the disruption of the British Empire… and the diminution of the offensive military power of Japan, with a view to the retention of our economic and political interest in the Far East. It is doubtful however that it would be in our interest to reduce Japan to the status of an inferior military and economic power. A balance of power in the Far East is as much to our interest as a balance of power in Europe.” (emphasis added)

Admiral Stark was not optimistic of Britain’s ability to remain in the war and as a result he recommended an immediate, intentional build up of U.S. Army and Navy capability. He wrote, “Until such time as the United States should decide to engage its full forces in war, I recommend that we pursue a course that will most rapidly increase the military strength of both the Army and the Navy, that is to say, adopt Alternative (A) without hostilities.”

President Roosevelt took Stark’s recommendations regarding the build up of the nation’s military capability, but President Roosevelt soon concluded that Nazi Germany posed the greatest global threat. The Plan Dog memorandum recommended that if the United States were forced into war against both Germany and Japan, it should fight defensively in the Pacific while concentrating resources on defeating Germany in Europe. As a result U.S. rearmament focused heavily on the Atlantic theater, increasing support was given to Britain through Lend-Lease, and the Navy was deeply engaged in convoy protection in the Atlantic and already clashing with German submarines.

Because Roosevelt wanted to prevent Japan from expanding while the U.S. focused on Europe, Washington set out to deter Japanese expansion through economic pressure rather than immediate war. Japanese diplomats and naval intelligence closely followed these developments. Tokyo concluded that the United States expected eventual war with Germany, were prioritizing European commitments and so the U.S. resources would be divided between two oceans. From the Japanese perspective, this created a temporary window of opportunity in the Pacific.

The “Germany First” strategy shaped Japanese thinking in two ways. First, it suggested that the United States might avoid a prolonged Pacific war if forced to fight Germany simultaneously. Second, Japanese planners believed that if the Pacific Fleet were crippled, the United States would be strategically compelled to concentrate on the European war. This assumption encouraged the idea that a surprise strike could secure time for Japan to seize Southeast Asian resources, establish a defensive perimeter in the Central Pacific, and force the United States to negotiate their exit from the Asia-Pacific conflict

The unintended consequence of all this was “Plan X” – not envisioned by Admiral Stark: war with the Axis allies, a two-ocean war, all initiated by Japan’s attack on Pearl Harbor.  Japan’s reasoning underestimated American political and military capacity. Instead of forcing strategic restraint, the attack on Pearl Harbor produced immediate ramp-up in U.S. mobilization and a long-term industrial expansion that Japan could never hope to match.

Image credit: various photographs from Naval Aviation Museum, National World War II Museum, and US Navy Archive | Plan Dog available online at the FDR Library at Marist College.

While the Imperial Japanese Army (IJA) lurched into escalation through a series of “incidents” in China and suffered defeat at Nomanhan at the hands of the Soviets, the Imperial Japanese Navy (IJN) followed a very different strategic logic. It was one that was more calculated and globally oriented, though ultimately no less expansionist.

Both Japan and the U.S. were adherents of the theories of Alfred Thayer Mahan (1890) who posited that national greatness is inextricably linked to sea power, defined as the ability to control vital maritime trade routes and project naval force. Mahan argued that a large, concentrated, offensive, steam-driven navy (as opposed to sail) supported by merchant shipping and overseas colonies, is essential for securing economic wealth and international influence.

By the early 1930s, the IJN had concluded that Japan’s survival depended on maritime access to resources. As such, it was clear that the decisive threat was the United States, not China or the Soviets (IJA’s concerns). IJN leaders, many of whom had served or studied in the United States, knew war, if it came, would be long, decided by naval forces, and dependent on control of the seas. This contrasted sharply with the Army’s fixation on continental expansion, border clashes and the ideological fixation against communism.

Decisive Battle Doctrine

The Navy’s planning revolved around kantai kessen (decisive fleet battle) which is described in a previous post: War Plan Orange. In short, the operational concept was to allow the U.S. Pacific Fleet to steam west 3,000 miles to the Western Pacific (Mahan’s theory was that for every 1,000 miles of ocean transit a fleet would lose 10% of its combatant strength). But along the way to attrit the U.S. Fleet with submarines and air attacks. The now weakened U.S. Fleet would be destroyed in a decisive surface battle in Japanese waters.

This doctrine was at the root of naval construction efforts: battleships, cruisers, destroyers, and aircraft carriers. The IJN was at the forefront of aviation, not only for deployment on carriers, but also for island-based airfields across Micronesia (Truk, Saipan, Palau and others). Such installations were sited on expected lines of advance of the US Fleet and served as “unsinkable aircraft carriers.” In this same vein, Japan emphasized long-range naval aviation, knowing that would be a key to success in the open waters of the Pacific. The Japanese also greatly expanded their submarine fleet.

The IJN and China 

When the Army expanded the Sino-Japanese war after the Marco Polo Bridge Incident, the Navy viewed it as a dangerous distraction from the larger strategic threat. Nonetheless, the Navy took on the natural role of blockading the Chinese coast, seizing key ports (Shanghai, Canton), and protecting maritime supply lines for Army forces. At the same time, the IJN took the opportunity to develop experience in long-range bombing by extensive naval air bombing of Chinese cities. The Navy hoped the whole “China affair” would quickly move to a political settlement so that resources and attention would focus on the coming naval battles

Internal Navy Debate: Treaty Faction vs. Fleet Faction

The Washington Naval Treaties of 1922 divided the IJN for the next 20 years. The resulting factions still mattered right up to 1941. In short, the Treaty Faction favored naval arms limitation, feared war with the U.S. and preferred diplomacy and gradual expansion. The Fleet Faction rejected treaty limits as shameful and dishonorable, sSought parity through qualitative superiority, and held that war with the U.S. was inevitable. By the late 1930s, the Fleet Faction dominated, especially after Japan withdrew from naval treaties in 1934 and began to build new combatants exceeding the limitation of the treaty. A key concept of the Fleet Faction was parity with the United States. While they knew the U.S. could outbuild Japan, they also knew that the U.S. was required to be a two-ocean navy. The Fleet Faction did not have many officers who were familiar with the U.S. industrial capacity or resources. Their basic assumption of parity in the Pacific was seriously wrong, and in addition, the focus on combatants severely diminished the production of merchant shipping and especially fleet oil tankers. In 1939, despite having a large merchant marine, Japan still relied on foreign-flagged vessels for nearly 30% to 40% of its shipping needs to sustain its economy, particularly for raw materials and oil. This persisted even into 1941. Japan’s military and industrial goals meant that it had to import 94% of requirements for oil, aviation fuel, gasoline, lubricants, and general purpose oil-based products.

Japan’s reliance on pre-war, Allied-flagged tankers, which ceased upon war declaration, left them with a massive logistical gap. Japan did not possess enough specialized oil tankers to adequately transport oil from Southeast Asia (the “Southern Resource Area”) to Japan after Pearl Harbor. In 1941 Japan required 32 million barrels of oil annually. This equated to 5 million (dead-weight) tons of shipping. Japan’s tanker fleet was inadequate, with only 49 merchant tankers (approx. 587,000 tons) available at the start of the war – only 10 percent of their needs. The lack of tankers was a critical failure in planning, as Japan failed to prioritize building enough tankers to secure their oil lifeline. While they quickly conquered oil fields, allied submarines and aircraft sank tankers faster than they could be replaced, severely crippling the oil supply line. 

IJN Operational Planning

The Army’s 1939 defeat by the Soviets at Nomonhan had an impactful, yet indirect effect on naval policy. The IJN concluded that continental expansion (China, Siberia, Mongolia, etc) was a strategic dead end. As such Japan must look south, not north. This reinforced the Navy’s preferred Southern Advance (Nanshin-ron) to Southeast Asia, the Dutch East Indies, and British Malaya

From the autumn of 1939 forward, naval war plans increasingly assumed U.S. embargoes and thus the need for preemptive action. Even then IJN leaders repeatedly warned the Diet and the Emperor about U.S. industrial superiority, repeatedly stressing that a long war with the United States could not be won. Oil reserves sufficient for roughly 18–24 months; after that, the fleet would be immobilized and any war fought later would be unwinnable.

No one expressed this more bluntly than Admiral Yamamoto, the architect of the Pearl Harbor attack, who warned that Japan could: “Run wild for six months… but I have no confidence after that.” It was sober professional judgment shared widely in naval circles.

The IJN lived with a deep internal contradiction. It understood with remarkable clarity that Japan could not win a long war against the United States, yet it simultaneously embraced plans that assumed a short, decisive victory would somehow occur. This was not simple irrationality. It was a coexistence of strategic realism and catastrophic optimism, reinforced by culture, doctrine, and institutional pressure.

Knowing a long war was unwinnable, it was clear that realism led not to peace, but to a compressed decision space. Diplomacy required abandoning China which was politically impossible. Waiting meant fuel exhaustion which was strategically fatal. Therefore, war now was preferable to war later. This logic did not say Japan could win a long war. It said Japan must force a short one.

The planning for the Attack on Pearl Harbor captures the paradox perfectly. The plan was realistic: neutralize the U.S. Pacific Fleet early. buy time to seize oil-rich territories, and establish a defensive perimeter too costly to break. The plan was catastrophically optimistic because it hoped the Americans would lose the will to fight, the U.S. would seek to negotiate after early setbacks, and so Japan could dictate terms before U.S. industrial power fully mobilized. Naval planners did not believe Japan could outbuild the U.S. They believed it could outshock it.

War Games

In the years before 1941, the IJN prided itself on war gaming as a mark of scientific modernity. They were conducted at the Naval War College; using detailed maps, counters, and probability tables; and overseen by highly trained staff officers. These war games were treated as tools for refining doctrine, proof of intellectual seriousness, and reinforcement of professional military identity. But they were not neutral experiments. They were embedded in the doctrine of decisive battle thinking.

Nearly all IJN war games began with non-negotiable assumptions: war would be decided by a single climactic encounter, the U.S. forces would advance methodically across the Pacific, and Japan would attrit the enemy and then strike decisively. Because these assumptions were never questioned, war games tested how to win the decisive battle not whether the strategy itself made sense. This meant strategic failure was excluded by design, including one of the most important assumptions: attrition. 

To give you an idea, IJN war games consistently assumed elite pilots survived at implausible rates, ignored replacement shortfalls, underplayed maintenance and fatigue and treated fuel and logistics as abstract variables. Attrition was systematically minimized.  Why? Because acknowledging attrition meant acknowledging time and time favored the United States. Thus, war games preserved optimism by compressing time out of the model.

The War Games always modeled the success of the decisive battle. It never modeled the war of attrition in which they were engaged.

The Fatal Flaw

What realism failed to penetrate was American political culture. While IJN leaders understood U.S. industry. They underestimated the U.S. public reaction of rage, the resulting unity, and capacity to “turn on a dime” to a war economy.  Japan achieved the shock it sought but not the reaction. Instead of weakened resolve, Pearl Harbor produced total mobilization, political unity, and a war effort that erased Japan’s initial advantages within a year. By December 1942, a year after Pearl Harbor, the U.S. was on the offensive having achieved a decisive result at the Battle of Midway, was close to driving the IJA from Guadalcanal, and was turning back the Japanese in New Guinea. Meanwhile, the shipyards and factories were producing ships, planes and pilots at rates that would soon overwhelm the Japanese. At the same time the Japanese merchant fleet was being methodically reduced by unrestricted submarine warfare.

Image credit: various photographs from Naval Aviation Museum, National World War II Museum, and US Navy Archive.

When discussing the rise of militarism in Japan’s Meiji Era, it was mentioned in passing that Japan adopted a British model for its Navy and a Prussian model for its Army. Japan’s preference for Prussian/German military models was not accidental or sudden. It grew directly out of choices, experiences, and disappointments made during the late Tokugawa and early Meiji years. 

By the late Tokugawa Shogunate period there were groups that were imperial loyalists and wanted to end the rule of the shoguns and reform the nation under the Emperor. The tensions ultimately lead to the Boshin War (1868–1869)  which pitted the imperial loyalists (primarily the Satsuma, Choshu, and Tosa domains) against the Tokugawa shogunate and its allied northern domains. The Shogunate forces had taken on French military methods, tactics, and weapons. They failed to save the Tokugawa Shogunat.

The victorious imperial loyalists who formed the Meiji Era drew lessons from their opponent’s defeat: (1) military reform could not be separated from political legitimacy and national unity, (2) the shogun supporters had adopted methods tied to a fallen regime (losers in the Franco-Prussian War). This stigma mattered enormously in Meiji political culture.

What Japan saw in Prussia was a small-to-mid-sized state defeating a great power with victory through universal conscription, a professional general staff, transportation and mobilization planning, and tight civil–military integration. To Meiji leaders, Prussia looked like Japan: late-developing, resource-conscious, and surrounded by potential enemies. Of supreme importance was that Japan needed a land army first, to suppress internal revolts and deter Russia and China.

Prussia offered something France and Britain did not: a theory of the army’s constitutional role. The key ideas were that the army serves the state (in this case, the Emperor); the officer corps embodies loyalty, discipline, and moral authority; and civilian politicians do not micromanage military doctrine. These principles aligned seamlessly with Emperor-centered legitimacy, fear of partisan politics, and the desire to prevent another “shogunate.” The Army would be a servant to the Emperor and therefore the State. Japan did not simply copy Prussia. It chose Prussia because Prussia solved Japan’s Meiji-era problems.

The Meiji Constitution encoded Prussian assumptions with the army and navy answering directly to the Emperor; military ministers required active-duty officers, and the Diet (Parliament) had limited control over defense policy. This arrangement prevented party politics from controlling the military and reflected Prussian constitutional monarchy rather than British parliamentary supremacy.

In the short term, Japan rapidly created  a modern, disciplined army that experienced success in the Sino-Japanese War (1894–95) and Russo-Japanese War (1904–05). But along with that success came an environment where the seeds of later insubordination and factionalism were sown. 

• The military had weak civilian oversight (the military occupied 4 seats in the cabinet and held a virtual veto over any decisions by civil government), 
• Military autonomy was institutionalized by the failure/inability of the civil government to control military operations or hold military leadership responsible (examples include the Mukden Incident in 1931, the Marco Polo Bridge incident in 1937 and the Nomanhan Incident in 1939). The Marco Polo incident was the action that began the 2nd Sino-Japanese War which was the start of the larger Asia-Pacific War, and 
• Radical factions within the military had little qualms about assassinating civil leaders, including the Prime Minister, that they felt were obstructing their aims.

Ironically, the very features that appealed to the first generation of Meiji leaders were the root causes that destabilized civilian government in the 1930s and contributed to the start of the Asia-Pacific War.

Image credit: various photographs from Naval Aviation Museum, National World War II Museum, and US Navy Archive.

In the post China and Japan: A History, it was noted that as early as the late 16th century, Japan believed it had surpassed China as a nation. It was then that Toyotomi Hideyoshi, the most preeminent daimyo, had unified all of Japan, brought an era of internal peace – and set about to invade China. In effect he was planning to claim for Japan the role traditionally played by China as the center of the East Asian international order. His first step was to invade Korea, a vassal state of China, and establish a strategic buffer. The conflict ended in 1598 with the withdrawal of Japanese forces from the Korean Peninsula after a military stalemate in Korea’s southern provinces. 

But what is of interest is that this memory seems to have set a model for national destiny and success: a unified government with a warrior-culture dominated society (samurai), a reasonable naval force available, and a vision of regional leadership as ordained by the gods. And in the background was the Imperial line, descendents of the sun goddess Amaterasu. 

Japan moved into the Tokugawa shogunate era, ending this period of expansionism. By now China remained a cultural source but no longer considered politically superior. But neither did Japan see itself as categorically superior to Asia. Asia was still a Sinocentric cultural world. China was admired as a source of classical learning, moral philosophy, and bureaucratic norms of governance. Korea was viewed as culturally refined and civilized. Japan’s self-image was distinct, but not hierarchical in a racial or civilizational sense.

But at this juncture of history, the Tokugawa shogun initiated policies designed to limit the access of the world to Japan. This seems to be the point Japan’s history when the seed had been planted: seeing itself as apart and superior to its Asian neighbors

Historians generally agree that Japan’s sense of being apart from and ultimately superior to its Asian neighbors did not emerge all at once. It developed in stages, with a decisive shift occurring from the 1870s through the early 1900s, as Japan’s leaders reinterpreted identity, civilization, and power in a rapidly changing world. It was the beginning of the Meiji Era. The decisive rupture in Japan’s view of itself and its Asian neighbors came after contact with Western imperial power. 

Key leaders in Meiji Japan realized that western powers ranked nations by a different measure of civilization, military strength, and institutional stability. At the same time Japan could see that other Asian states were being colonized or humiliated. Japan’s leaders concluded that Asia as a whole occupied a dangerous lower tier in the global order. It became clear to the leaders that Japan’s survival required reinvention, not merely reform. This produced a new logic: If Asia is treated as backward, Japan must prove it is not truly Asian in the Western sense.

Leaving Asia

The most explicit articulation of separation came from Fukuzawa Yukichi. In the mid-1880s, Fukuzawa argued that China and Korea were stagnant and resistant to reform. With his ideas of social darwinism, he concluded that the world order was like a universal ladder and it was evident that Japan was climbing it faster than its Asian neighbors. His conclusion was that Japan should “leave Asia” intellectually and institutionally. This was not a call for conquest, but it clearly ranked Asian societies hierarchically and framed Japan as exceptional within Asia. This moment marks the conceptual break: Japan begins seeing itself as no longer fully “of” Asia.

Military success transformed Fukuzawa’s theory into conviction. After defeating China in the 1890s Japan became the first Asian power in modern times to defeat another Asian state using Western-style warfare. Victory was interpreted not just as strategic success, but as proof of civilizational advancement and evidence of national superiority. Discourse within Japan’s political, educational, and other civil institutions – including the newspapers and periodicals – increasingly portrayed China as decadent and obsolete. Korea was seen as weak and incapable of self-rule. It is at this point that Japan began to assert a cultural claim of superiority, which was slowly shifting from cultural claim to demonstrated fact.

That sense of shifting hierarchy in the Asian sphere was amplified and accelerated with Japan’s defeat of Russia in the Russo-Japanese War of 1904-1905. For Japan it confirmed parity with Europe and elevated Japan from more than a regional leader to an equal of great power on the world stage. For Japanese elites, the implication was stark.  Other Asian nations had been victims of western power. Japan was a victor. From this point on, Japanese superiority was framed as historical, moral, and increasingly racial.

By the early 20th century, Japan’s self-image had evolved and hardened into a view that held Japan as the preeminent leader and guide of all Asian nations who were viewed as pupils or dependents. This mindset underpinned colonial rule in Korea (annexed in 1910), expansion in China in the 1930s and claims of “liberating” Asia while dominating it as time moved into the 1940s. What began as defensive differentiation was assertive hierarchy. When their neighbors resisted, it was interpreted as backward, uncivilized and above all, a lack of gratitude.

In short, Japan first separated itself from Asia to survive incursion by the West. In time, ideologically driven by social darwinism, bolstered by military victories in China,  then came to believe it had surpassed Asia altogether. Japan took on a great-power identity as the hierarchy of Asian nations hardened in Japan’s estimation with Japan having surpassed any other Asian nation and attained parity of honor and prestige among modern nations – or so they assumed.

Education and Propaganda

What is interesting is that the government-supplied elementary and upper school textbooks’ content parallel this evolution. Early Meiji textbooks were reformist rather than openly chauvinistic. They taught that civilization (bunmei) as a universal, linear process that allowed the observer to rank nations by technology, institutions and moral discipline of the people and the leaders. China and Korea were depicted as once-great civilizations grown stagnant and bound to outdated customs. Japan, by contrast, was presented as energetic, adaptive, and willing to learn from the West.

By the late 1800s the textbooks introduced moral education, but not in the traditional sense. It now linked national character to the nation’s destiny. Japan was portrayed as loyal, disciplined, and public-spirited – characteristics lacking in their Asian neighbors who were described as corrupt, disunited and passive. It was at this point in history the Emperor issued an Imperial Rescript on Education, which centered on loyalty to the Emperor; framed Japan as a moral community, not just a state; and cast other Asian nations as lacking a moral unity.

After the First Sino-Japanese War the supplied history texts rewrote East Asian history in the framework of  decline vs. renewal.  China was described as a nation that was a living fossil dependent on the achievement of their ancestors, refusing to renew. The world passes them by in terms of technology and power. In China’s refusal to renew, Japan was cast as the rightful heir to “true” Asian civilization, now modernized. It was at this same point in time that mass circulation media became accessible. Such media consistently portrayed Japanese soldiers as loyal, trained, possessed of samurai spirit and humane. Chinese soldiers were portrayed as chaotic, cruel, or cowardly. This war marked the first time military victory was presented as proof of civilizational hierarchy, not merely strategic success.

Victory in the Russo-Japanese War (1904-5) transformed the tone and content of school materials. Geography and civics texts ranked nations explicitly. Japan was placed alongside Europe while Asia was treated as problematic: weak, unstable, in need of order. The lessons were clear: Japan had a special destiny, strength equaled virtue, and power justified leadership. In popular media Japan was portrayed as the champion of Asia against the West, protector of the childlike other Asian nations. Japan was seen in the role of  paternal superiority.

After the annexation of Korea (1910) when Japan entered its empire-building era, textbooks depicted colonies as historically incapable of self-rule and now the beneficiaries of Japanese administration. That was in Japan. In Korea and other regions, colonial textbooks taught Japanese history as the main narrative in that it was a history to emulate centered on loyalty to the Emperor as universal virtue. Popular children’s books and magazines showed colonial subjects smiling under Japanese tutelage.

By the 1930s the theme of textbooks and media had evolved from simple Japanese superiority to Japanese destiny. History became overtly teleological, showing Japan’s rise as natural and moral, with Japan positioned as destiny’s leader in the western Pacific.  Japanese military “adventures” were seen as defensive measures that were historically inevitable. Resistance to this evolution and tide of history was irrational as the rest of Asia was clearly incapable of progress without Japanese leadership.

It was the era of a different colonialism masked under the language of “co-prosperity” that gave an acceptable face to Japan’s deeply entrenched sense of superiority.

Image credit: various photographs from Naval Aviation Museum, National World War II Museum, and US Navy Archive.

More than two months ago, we started a companion series to the 2025 series on the Asia- Pacific War. The focus of that series was less about how or why it started, but about its ending. You can read that series here. The focus of this 2026 series has been exploring how the currents of history brought the U.S. and Japan to the events of December 7, 1941 that was a final domino to fall and bring the United States into the firestorm that was the already on-going Asia-Pacific War. 

In the previous post, Dialogue to War, described the departure of the Japanese fleet to attack Pearl Harbor while discussions were still underway, the final throes of diplomacy between Japan and the United States, and the result:

“A small fire at the Marco Polo Bridge in 1937 spread to Manchuria, northern China, key Chinese ports, and French Indochina. On December 7, 1941 by attacking the U.S. Pacific Fleet at Pearl Harbor, the growing fire became the full firestorm of the Asia-Pacific War that lasted until September, 1945 at the cost of more than 30 million Asian lives…Such was the path to the Asia Pacific War.”

Perhaps it was the inevitable consequence of Admiral Perry’s uninvited sail into Tokyo Bay in 1853 using “gunboat diplomacy” to force the isolated Japan during the Tokugawa Shogunate to open up for trade. Or was that simply incidental to the movements already underway that led to the fall of the Shogunate and the beginning of the Meiji Era centered on the Emperor. A coincidence of timing? Within the resource poor home islands, the population was already outstripping the ability of the nation to feed itself – a trend that continued into the 20th century. Were the internal pressures within Japan driving the nation to look for land and resources to sustain itself? 

Perhaps it was the ascendancy of the military within the halls of power. Or the basic structure of the Meiji Constitution that provided virtually no civilian oversight to the military, leaving the only “firewall” as the Emperor who showed no inclination to involve himself in such affairs? All led to a military that seemed to have acquired all the bushido spirit of the samurai but no longer had the internal battles to seek glory and honor. It began a history of seeking such glory on the Asian mainland.

The military was not the only element of Japanese society that was looking outside the home islands. Contact with the West brought new observations and with them new insights and conclusions. The idea of “social darwinism” reshaped elite thinking leading to a re-evaluation of their views of China and East Asia after the Meiji Reforms. The core assumptions absorbed in Japan was that the nations compete like organisms in which there will always be a struggle for the resources that make life flourish and history will be governed by conflict in which weak states are absorbed or eliminated. Moral intention will not stave off extinction. For a nation that had long been invested in Confucian life where virtue and moral order are essential elements, the shift away from moral intentions to survival of the fittest, the natural pathway was imperialism and permanent competition for local, regional and global dominance.

It was a rapid shift away from traditional and classic ways of understanding the world order because they watched it unfold in the living laboratory called China. For Japanese elites and leaders, social darwinism was evident in the Opium Wars, the Unequal Treaties, loss of economic control, and disintegration of internal cohesion. China became the empirical proof that moral civilization without power equals extinction.

In 1870, Fukuzawa Yukichi published “Conditions in the West,” a meditation based on his observations in Europe and America. He introduced the concept that international relations operate by power, not morality and as a result weak nations are exploited regardless of virtue. He pointed out that China, while being morally refined, is politically helpless, no nation at all, and is subjugated to the economic interests of the non-Asian world powers. Among Japanese elites the dialogue asserted that Asia was collectively at risk, only strength and modernization could prevent subjugation, and equality would be granted only to those who could enforce it. Thus national survival required military parity, industrial capacity and territorial buffers

In 1882 Katō Hiroyuki published “A New Theory of Human Rights,” work in which Katō explicitly rejected natural rights, arguing that rights arise from power. He applied what was essentially evolutionary logic to politics: “The strong rule; the weak are destroyed—this is the law of nature.” His work marks the moment when evolutionary struggle became normative political theory within Japan. This movement in political thought was more fully described in the post Japan and Social Darwinism. 

By the time Japan entered the post-WW1 era, it began to see itself as the only qualified leader of Asia for the modern world, a guardian of Asia against incursions by the West, and possessed of the destiny to assume it role of leadership a greater Asian prosperity sphere: an oriental Monroe Doctrine.

Jumping ahead to December 1941, Japan was bogged down in China fighting a war it started and, despite early successes, had very little chance of winning but every chance of experiencing the endless quagmire that had always been China. It is akin to the dog that chases the car, catching up to it, and clamping onto the bumper…now what? The fighting in China was already draining Japanese national reserves, was being fueled (literally) by oil and gasoline from the U.S., and was beginning to drastically reduce the standard of living among the Japanese people on the home islands. Why would Japan start a conflict with the U.S.?

It was a battle that the leaders of Japan knew they could not win. A war the Japanese government’s Total War Research Institute reported there was no chance of winning. Their actions were not rational; made no sense to the Western mind. Even the best minds in Japan argued against the possibility of success. But as Prime Minister Tōjō once remarked: “Occasionally, one must conjure up enough courage, close one’s eyes and leap off the veranda of the Kiyomizu Temple.”

It wasn’t rational by any standards of Western thinking steeped as in the biblical admonition of caution and wisdom: “Or what king marching into battle would not first sit down and decide whether with ten thousand troops he can successfully oppose another king advancing upon him with twenty thousand troops?” (Luke 14:31). The combined power of the western allies would bring to bear far more than a 2:1 advantage. Surely, Japan would “count the cost.”

It wasn’t rational. But what was it? As I try to “wind down” this series, that question will be the path of inquiry. Previous posts have laid a foundation in terms of prior U.S.-Japanese contact, economic issues, financial and market pressures, political and diplomatic conflict, and a range of core issues. Future posts will draw on that foundation (and include links to those posts rather than repeat their argument in whole) with a goal of answering the question of “why would Japan force the United State into the Asia-Pacific War?” It is a question of history but also an opportunity for “lessons learned”  for application to future conflicts.

Image credit: various photographs from Naval Aviation Museum, National World War II Museum, and US Navy Archive. |

On November 26, Hull presented what became known as the Hull Note, demanding full Japanese withdrawal from China and Indochina and adherence to multilateral principles. Within Japan, the note was discussed in emergency meetings and ultimately rejected as unacceptable. Hull delivered what was seen within Japan as an ultimatum. It required Japan to:

• withdraw all military forces from China and Indochina.
• end support for any puppet regimes (i.e., dissolve Manchukuo).
• recognize the Nationalist government (Chiang Kai-shek) as legitimate in China.
• abandon the Tripartite Pact commitments.
• agree to non-aggression pacts and equal commercial opportunity in the Pacific.
• and in return, the U.S. would resume normal trade, including oil.

For leaders who had already committed themselves to war preparation, it confirmed that diplomacy could not secure Japan’s objectives. 

Japan’s leaders viewed this ultimatum as humiliating and as requiring them to give up everything they had fought for since 1931. Yet, Japan’s oil reserves were running out. The Navy warned that by late 1942 or early 1943, Japan would be unable to support its armed forces anywhere in the Pacific.

Historians have asked if Hull’s note was a rogue act and the historical record is clear that it was not. Negotiations were dragging on and MAGIC intelligence (diplomatic not military) pointed to Japanese troop movements toward Southeast Asia along with repositioning of naval assets in that general direction. Roosevelt and his Cabinet were increasingly suspicious of Japanese intentions, seeing the protracted delays in responses as “stalling” to complete their war footing.

Going to War

The Second Imperial Conference was held November 5, 1941 after weeks of Army–Navy–Cabinet debates. It was decided that Japan would give negotiations until early December. If no settlement was reached, Japan would launch war against the U.S., Britain, and the Netherlands. The military finalized operational plans — the Navy would strike Pearl Harbor while also moving into Malaya and the Dutch East Indies.

There was a final Imperial Conference on December 1, 1941. The cabinet reported to Hirohito that negotiations had failed. The Army and Navy both argued that war was now unavoidable. Hirohito approved the resolution that war with the United States, Britain, and the Netherlands would begin in early December. Diaries record Hirohito as somber, but he gave no objection. His silence ratified the decision. Hirohito performed the ritual reading of the imperial rescript that authorized hostilities. The debate was closed.

In his post-war memoirs, Lord Privy Seal Kido wrote that Hirohito considered the Hull Note a “humiliation” Japan could not accept. There are layers of reasons why, but from Japan’s perspective the U.S. was treating Japan like a defeated power before a shot was fired. Kido recorded that Hirohito was deeply offended that the U.S. would presume to dictate terms so sweeping without acknowledging Japan’s own status as a great power. Prime Minister and Foreign Minister Tōgō wrote that it was “tantamount to a demand for unconditional surrender” for a war that had not begun.

Japan had spent a decade building the “New Order in East Asia” and the Greater East Asia Co-Prosperity Sphere. The Hull Note demanded Japan dismantle these achievements entirely — which would have been politically impossible for the Army, and a blow to Hirohito’s prestige as the figurehead of expansion. 

In Japanese political culture, especially at that time, “losing face” before domestic and international audiences was nearly as bad as military defeat. If Hirohito had accepted the Hull Note, he would have been remembered as the Emperor who surrendered Japan’s destiny without a fight. Even though he disliked war, he considered acceptance dishonorable and humiliating — worse than risking war with the U.S.

On the same day the Hull Note was received, November 26th, the Japanese First Air Fleet (Kido Butai) — the carrier strike force that attacked Pearl Harbor — sailed. It consisted of 6 aircraft carriers, 2 battleships, 3 cruisers, 9 destroyers, 8 oilers. At dawn on December 7 it launched its first wave of aircraft. 

The Asia-Pacific War in the Pacific expanded to include the United States, Great Britain, the Netherlands, Australia, New Zealand, and in time a host of other nations. 

A small fire at the Marco Polo Bridge in 1937 spread to Manchuria, northern China, key Chinese ports, and French Indochina. On December 7, 1941 by attacking the U.S. Pacific Fleet at Pearl Harbor, the growing fire became the full firestorm of the Asia-Pacific War that lasted until September, 1945 at the cost of more than 30 million Asian lives.

It was a battle that the leaders of Japan knew they could not win. A war the Japanese government’s Total War Research Institute reported there was no chance of winning. Their actions were not rational; made no sense to the Western mind. Even the best minds in Japan argued against the possibility of success. But as Prime Minister Tōjō once remarked: “Occasionally, one must conjure up enough courage, close one’s eyes and leap off the veranda of the Kiyomizu Temple.”

Such was the path to the Asia Pacific War.

Image credit: various photographs from Naval Aviation Museum, National World War II Museum, and US Navy Archive. 

The Hull note, in its essence, was the same four principles that Secretary Hull had presented to the Japanese since 1937.  The note, in part, reads as follows:

The Government of the United States and the Government of Japan both being solicitous for the peace of the Pacific affirm that their national policies are directed toward lasting and extensive peace throughout the Pacific area, that they have no territorial designs in that area, that they have no intention of threatening other countries or of using military force aggressively against any neighboring nation, and that, accordingly, in their national policies they will actively support and give practical application to the following fundamental principles upon which their relations with each other and with all other governments are based:

The principle of inviolability of territorial integrity and sovereignty of each and all nations.

The principle on non-interference in the internal affairs of other countries.

The principle of equality, including equality of commercial opportunity and treatment.

The principle of reliance upon international cooperation and conciliation for the prevention and pacific settlement of controversies and for improvement of international conditions by peaceful methods and processes. 

Historians do not agree on a single meaning or intention behind the Hull Note of November 26, 1941. As noted in other parts of this series, depending on when the historical research was conducted, what sources were available, one reaches a different conclusion. 

Early postwar and revisionist historians portrayed the Hull Note as a de facto ultimatum that made war inevitable. The core argument is that the demand for complete Japanese withdrawal from China and Indochina amounted to strategic capitulation. Given Japan’s internal politics, acceptance was politically impossible. In this view, the U.S. leadership, especially President Roosevelt, either knew this or was willing to accept war as the price of principle. Most historians now see this view as overly deterministic and insufficiently attentive to the reality of Japanese internal politics, decision-making, and control by the military.

The dominant 20th century view holds that the Hull Note was not an ultimatum, but a reiteration of long-standing U.S. policy principles. The note did not introduce new demands; it restated positions held since 1937–1938 and it left room for negotiation if Japan chose to engage. The conclusion is that the U.S. did not intend it as a war trigger, but as a repetition of the clear baseline based on principles accepted by modern nations. Secretary of State Cordell Hull himself insisted the note was a “statement of principles”, not a take-it-or-leave-it demand. Perhaps naively, some U.S. officials continued to believe Japan might choose restraint given the note avoided explicit threats or deadlines. One critique of this view is that it does not pay enough attention to how Japanese leaders perceived the note.

Most contemporary historians adopt a synthetic view: the Hull Note neither caused nor prevented war, but clarified that war was already likely. The argument goes as follows:

• By late November, Japan had already committed internally to war, pending a final diplomatic check.
• The Hull Note exposed the incompatibility of U.S. and Japanese strategic visions.
• It removed ambiguity, making continued diplomatic hedging impossible.

In this view, the note functioned less as a trigger than as a diagnostic moment. It must be remembered that Japan’s Imperial Conference of September 6, 1941 had already set war preparation in motion, the Japanese cabinet debated war before receiving the Hull Note, and the note was used in Tokyo primarily to justify a decision already made, not to cause it.

A crucial modern insight is the asymmetry of interpretation:

• Americans saw the note as a firm but reasonable statement.
• Japanese leaders saw it as a demand for humiliation and abandonment of empire.

This gap, rather than bad faith alone, helps explain why the same document could be viewed as both principled and provocative.

Most historians today conclude that the Hull Note was not designed to force war, was not a sudden escalation, did not meaningfully alter Japanese military timelines but it did clarify that no negotiated middle ground remained. In short, the Hull Note was less the cause of war than the moment when diplomacy finally caught up with strategic reality.

From Dialogue to War

On November 26, Hull presented what became known as the Hull Note, demanding full Japanese withdrawal from China and Indochina and adherence to multilateral principles. Within Japan, the note was discussed in emergency meetings and ultimately rejected as unacceptable. Hull delivered what was seen within Japan as an ultimatum. It required Japan to:

• withdraw all military forces from China and Indochina.
• end support for any puppet regimes (i.e., dissolve Manchukuo).
• recognize the Nationalist government (Chiang Kai-shek) as legitimate in China.
• abandon the Tripartite Pact commitments.
• agree to non-aggression pacts and equal commercial opportunity in the Pacific.
• and in return, the U.S. would resume normal trade, including oil.

For leaders who had already committed themselves to war preparation, it confirmed that diplomacy could not secure Japan’s objectives. 

Japan’s leaders viewed this ultimatum as humiliating and as requiring them to give up everything they had fought for since 1931. Yet, Japan’s oil reserves were running out. The Navy warned that by late 1942 or early 1943, Japan would be unable to support its armed forces anywhere in the Pacific.

Historians have asked if Hull’s note was a rogue act and the historical record is clear that it was not. Negotiations were dragging on and MAGIC intelligence (diplomatic not military) pointed to Japanese troop movements toward Southeast Asia along with repositioning of naval assets in that general direction. Roosevelt and his Cabinet were increasingly suspicious of Japanese intentions, seeing the protracted delays in responses as “stalling” to complete their war footing.

Going to War

The Second Imperial Conference was held November 5, 1941 after weeks of Army–Navy–Cabinet debates. It was decided that Japan would give negotiations until early December. If no settlement was reached, Japan would launch war against the U.S., Britain, and the Netherlands. The military finalized operational plans — the Navy would strike Pearl Harbor while also moving into Malaya and the Dutch East Indies.

There was a final Imperial Conference on December 1, 1941. The cabinet reported to Hirohito that negotiations had failed. The Army and Navy both argued that war was now unavoidable. Hirohito approved the resolution that war with the United States, Britain, and the Netherlands would begin in early December. Diaries record Hirohito as somber, but he gave no objection. His silence ratified the decision. Hirohito performed the ritual reading of the imperial rescript that authorized hostilities. The debate was closed.

In his post-war memoirs, Lord Privy Seal Kido wrote that Hirohito considered the Hull Note a “humiliation” Japan could not accept. There are layers of reasons why, but from Japan’s perspective the U.S. was treating Japan like a defeated power before a shot was fired. Kido recorded that Hirohito was deeply offended that the U.S. would presume to dictate terms so sweeping without acknowledging Japan’s own status as a great power. Prime Minister and Foreign Minister Tōgō wrote that it was “tantamount to a demand for unconditional surrender” for a war that had not begun.

Japan had spent a decade building the “New Order in East Asia” and the Greater East Asia Co-Prosperity Sphere. The Hull Note demanded Japan dismantle these achievements entirely — which would have been politically impossible for the Army, and a blow to Hirohito’s prestige as the figurehead of expansion. 

In Japanese political culture, especially at that time, “losing face” before domestic and international audiences was nearly as bad as military defeat. If Hirohito had accepted the Hull Note, he would have been remembered as the Emperor who surrendered Japan’s destiny without a fight. Even though he disliked war, he considered acceptance dishonorable and humiliating — worse than risking war with the U.S.

On the same day the Hull Note was received, November 26th, the Japanese First Air Fleet (Kido Butai) — the carrier strike force that attacked Pearl Harbor — sailed. It consisted of 6 aircraft carriers, 2 battleships, 3 cruisers, 9 destroyers, 8 oilers. At dawn on December 7 it launched its first wave of aircraft. 

The Asia-Pacific War in the Pacific expanded to include the United States, Great Britain, the Netherlands, Australia, New Zealand, and in time a host of other nations. 

A small fire at the Marco Polo Bridge in 1937 that spread to Manchuria, northern China, key Chinese ports, and French Indochina. On December 7th, by attacking the U.S. Pacific Fleet at Pearl Harbor, the growing fire became the full firestorm of the Asia-Pacific War that lasted until September, 1945 at the cost of more than 30 million Asian lives.

It was a battle that the leaders of Japan knew they could not win. A war the Japanese government’s Total War Research Institute reported there was no chance of winning. Their actions were not rational; made no sense to the Western mind. Even the best minds in Japan argued against the possibility of success. But as Prime Minister Tōjō once remarked: “Occasionally, one must conjure up enough courage, close one’s eyes and leap off the veranda of the Kiyomizu Temple.”

Such was the path to the Asia Pacific War.

Image credit: various photographs from Naval Aviation Museum, National World War II Museum, and US Navy Archive. 

In late September into early October, 1941Prime Minister Konoe floated the idea of a summit meeting with President Roosevelt. Konoe was increasingly convinced that Japan could not win a prolonged war with the United States, diplomacy through normal Foreign Ministry channels had stalled, and only a direct leader-to-leader meeting might override military rigidity on both sides. 

Konoe-Roosevelt Summit?

Roosevelt was intrigued but cautious. One of the great “what ifs” of the run-up to war was what if Roosevelt and Konoe had met. One of the problems for Konoe/Japan was the U.S. has already broken the Japanese diplomatic code (MAGIC). It was clear that Konoe did not have support of the Army, we understood that there needed to be unanimity among Japanese leaders directly advising the Emperor, and so it was clear that Konoe could not come to any meeting with the ability to commit the Japanese to anything agreed upon in any meeting. The fatal flaw was there was no real way to bypass the hardliners and militarists in Japan. 

Roosevelt had his own hardliners: the American First movement that did not believe that we should in any way be embroiled in foreign wars. They had already claimed Roosevelt was dragging the U.S. into war. So, if the President met Konoe without preconditions, opponents would accuse him of “appeasement” — the same word used against Britain at Munich in 1938. And hence Roosevelt insisted he needed “substantial evidence of sincerity” from Japan before he could even consider a summit.

Word was relayed via Ambassador Nomura that he might meet Konoe, but only if Japan showed good faith first. The US was the first to “put its cards on the table.” The US asked that:

• Japan must halt further aggression: no more moves into Southeast Asia or the Pacific.
• Respect the territorial integrity of China: withdraw from newly occupied zones and stop expansion.
• Renounce Axis obligations: the U.S. wanted assurances Japan would not support Germany if America entered the war in Europe.
• The U.S. would ease some trade restrictions. 

Japan’s counter proposal was

• U.S. to accept Manchukuo (Japanese puppet state of Manchuria) as legitimate.
• U.S. recognition of its “special position” in China, with acknowledgement of a new economic order in East Asia that included China
• Stop aid to Chiang Kai-shek’s Nationalist China 
• Stop reinforcing the Philippines and other U.S. Pacific outposts.
• Pledge to not interfere with Japan’s “Co-Prosperity Sphere.”
• Its alliance with Germany and Italy must be respected

At this point the positions were “oceans apart.” The Konoe–FDR summit was seriously “bandied about” in some channels, lingered tenuously into early October, and then disappeared entirely with Konoe’s resignation on Oct 18th. 

The Final Phase of Diplomacy

General Tōjō Hideki was appointed Prime Minister and immediately formed a new cabinet whose majority were military officers who supported the military move into Southeast Asia and war against the U.S. should diplomacy fail. The new cabinet directed the Foreign Ministry to draft a comprehensive proposal that might avert war while preserving Japan’s core positions in China. The draft took shape in late October and early November, under tight military oversight and with an explicit awareness of Japan’s dwindling oil reserves.  It would eventually construct two negotiating proposals: Plan A and Plan B.

“Plan A” was formally approved at an Imperial Conference on November 5, 1941. At the same conference, Japan also authorized continued military preparations and set a diplomatic deadline, making clear that negotiations would not be open-ended. The proposal was Japan’s first comprehensive peace proposal of the final negotiation phase. It was presented in Washington on November 7, 1941, by Ambassador Nomura (soon joined by Envoy Kurusu). Key details of the Japanese proposal included:

The proposal contained the following core elements:

• China: Japan would withdraw troops from most of China after the establishment of peace with Chiang Kai-shek. Manchuria (Manchukuo) was explicitly excluded from any withdrawal. Also, Japan insisted on a bilateral Japan–China settlement, not one imposed by the United States.
• Indochina: Japan promised no further military advance from Indochina into Southeast Asia. Japanese troops would be withdrawn from Indochina after peace was restored in East Asia, not immediately.
• Tripartite Pact: Japan reaffirmed adherence to the Tripartite Pact, while asserting it was defensive and did not threaten the U.S.
• Economic Relations: Restoration of normal trade relations, including access to oil. Mutual lifting of asset freezes. Economic cooperation between Japan and the United States.
• General Principles: Mutual non-aggression in the Pacific. Respect for territorial integrity as interpreted by Japan.

American officials concluded that the proposal did not require immediate withdrawal from China or Indochina and that what withdrawal was offered was at best contingent and vague while asking the U.S. to first restore trade and supply oil. The implication was that the U.S. would accept Japan’s continental gains. As a result, Proposal A was judged insufficient and evasive, though Washington did not immediately reject it outright. In fact, while Japan formally delivered its plan via diplomatic note, the U.S. never formally replied. Between Nov 12 and 15, Secretary Hull conveyed the U.S. position orally to Nomura (and later Kurusu) that Proposal A was insufficient:

• Conditional and delayed withdrawals from China were unacceptable
• Restoration of oil and trade could not precede concrete military withdrawal
• The U.S. could not recognize Japan’s “special position” in China

This was a clear negative signal, but not a formal diplomatic note. Japan understood the message. 

After U.S. officials made clear that Plan A would not be accepted, Prime Minister Tōjō directed the Foreign Ministry to prepare a minimal, provisional proposal designed primarily to secure short-term oil supplies while Japan completed military preparations. The draft took shape around November 15–18, with the Army and Navy insisting it be strictly temporary and not include withdrawal from China. The plan was approved at a Nov 19th Imperial Conference. The same conference reaffirmed Japan’s resolve to proceed with war preparations if negotiations failed, making clear that Plan B was a stopgap, not a compromise of peace. The proposal was presented in Washington on November 20, 1941, by Ambassador Nomura and Special Envoy Kurusu. It offered a temporary freeze on further military advances, limited Japanese withdrawals from southern Indochina, and non-aggression assurances, in exchange for partial unfreezing of assets and renewed oil shipments.

When the United States responded on November 26 with the Hull Note, Japanese leaders concluded that diplomacy had reached a dead end.

Image credit: various photographs from Naval Aviation Museum, National World War II Museum, and US Navy Archive.