After the May 1945 German surrender, arrangements were made for the Allies to meet in Potsdam, Germany. The topics were to settle the postwar arrangements for Europe and to reach agreement on coordinated Allied military operations against Japan. A month before the mid-July Potsdam Conference, President Truman met with his senior advisers to go over plans for ending the war with Japan and to prepare himself for Potsdam. In a 14 June memorandum to the service chiefs setting up this meeting, his Chief of Staff, Admiral Leahy, said the President wanted to:

“. . . discuss details of our campaign against Japan. He expects at this meeting to be thoroughly informed of our intentions and prospects in preparation for his discussions with Churchill and Stalin. He wants an estimate of the time required and an estimate of the losses in killed and wounded that will result from an invasion of Japan proper. He wants an estimate of the time and the losses that will result from an effort to defeat Japan by isolation, blockade, and bombardment by sea and air forces. It is his intention to make his decision on the campaign with the purpose of economizing to the maximum extent possible in the loss of American lives. Economy in the use of time and money cost is comparatively unimportant. I suggest that a memorandum discussion of the above noted points be prepared in advance for delivery to the President at the time of the meeting. . . .”

In the previous post we considered the basis of modern just war theory in the writings and reflections of St. Thomas Aquinas. His thoughts became the basis for reflection on wars prior to the 20th century. For example, in the 16th century the Dominican Francisco de Vitoria applied just war thinking to Spain’s wars of conquest in the Americas. While he rejected armed conflict against indigenous people for the cause of conversion, he argued that the Spanish explorers had freedom to be in the foreign lands and their defense was just.  Thomas’ thoughts were applied to conflicts between Christian monarchs, regional disputes, and the such. It was not until the 17th century that Hugo Grotius, De Jure Belli ac Pacis, used the theory and applied just war reasoning to the Thirty Years’ War and European state conflicts. His work was foundational in international law and guided legal-political thinking for centuries. It also reflected the changing nature of war in the western European world.

In a very different setting, during the Crusades of the 11th–13th centuries, medieval theologians and canonists defended the Crusades as just wars under Aquinas’ principles. Their understanding was that the wars met the criteria: legitimate authority in the Pope; a just cause in defense of pilgrims and recovery of holy places;  and the right intention, namely service to God. It was not until the late 16th century in the work of Francisco Suárez that “proportionality” was considered.

In May 1945, Germany surrendered unconditionally. Many commentators offer that this would have been the optimal time to organize discussions with the Allies about a negotiated peace, preempt Russian involvement in the Pacific War, and end the war on terms acceptable to Japan. No attempts were made – nor were they likely to have gotten “off the ground.” The mindset of the Council was devotion to the Ketsu-Go plan. Suzuki had zero possibility of reaching a unanimous Council position in order to present such an option to the Emperor.

Meanwhile, during this time period, Leyte has fallen, Luzon is all-but-defeated, Iwo Jima has been taken, and  Okinawa is in progress. Allied bombing and firebombing continues. The submarine blockade is tightening its hold. The last oil tanker reached Japan in March 1945. Japan had their oil, gas and aviation fuel reserves and no hope to replenish their stock – which was more than 1 million barrels.  At the same time B-29 sealane mining is grinding coastal sea traffic to a halt, naval shore bombardment continues and there is no decisive battle left save Okinawa (doubtful) or Ketsu-Go, the defense of the home islands.

In this time period Emperor Hirohito had asked for two reports: (a) Estimate of the World Situation (prepared by the Army staff) and (b) Sōri Daijin Hōkoku – “Report to the Prime Minister” (prepared by Admiral Sakomizu). Sakomizu was asked to produce an objective, comprehensive assessment of Japan’s military, economic, and social condition to guide decisions about continuing or ending the war. The report painted a grim and realistic picture.

In the modern age, the average Catholic looks to the Catechism of the Catholic Church to find guidance on the concept of just war. The Church teaches that war can be morally justified under certain conditions, which are rooted in the principles of just cause, legitimate authority, right intention, and proportionality. (Found in paragraphs 2307 to 2317). The conditions fall into three broad categories:

• jus ad bellum (before the war)
• Jus in bello (during the war)
• jus post bellum (after the war)

The first four conditions address jus ad bellum.

It was a busy month. Mounting military losses and the inability of Prime Minister Koiso to garner consensus within the War Council led to the collapse of the government and the appointment of Admiral Suzuki as Prime Minister. It takes time to form a government – and meanwhile there is a lot going on. Iwo Jima is reaching its bloody end just as Okinawa begins to unfold. The losses among land forces, naval personnel (viz. kamikaze) and especially among civilians will be horrific and impactful.

Some argue that April 1945 was a lost opportunity. Suzuki was the new prime minister and there are those historians who assert that he was an advocate for peace. That is probably wishful thinking. He was an absolute opponent of unconditional surrender but at the same time was a proponent of Ketsu-Go. He was not a hardliner like Army Chief of Staff Umezu and War Minister Anami, but one of his first acts was to sign a pledge presented by a delegation of generals from IJA/HQ that committed Suzuki to prosecute the war to its fullest as outlined in Ketsu-Go, the plan to defend the home islands to the bitter end – no surrender. Hardly a peace advocate.

The title may have caught your eye and caused you to wonder about the dates. Shouldn’t the War in the Pacific be dated from December 7, 1941, the attack on Pearl Harbor, until September 2, 1945 and the surrender of Japan aboard the USS Missouri? Certainly those are the dates which involved the United States and her allies. But war in the Asia-Pacific region had already started with the Sino-Chinese war, long simmering, but breaking out into open warfare in 1937. Japan had occupied Manchuria since 1931, but then invaded much of China from 1937 onward, including Beijing, Shanghai, Nanjing, and the coastal regions). French Indochina (Vietnam) was invaded next: the North in 1940 followed by the South in 1941. Well before Pearl Harbor troops were already in position to launch attacks against Cambodia, Laos, Thailand, Burma, Indonesia (Dutch East Indies), Malaysia and Singapore, Brunei and Borneo, Hong Kong, parts of New Guinea, the Marshall Islands, Truk, Palau, the Marshalls, and other Micronesian islands.  It should also be remembered that Japan ruled the Korean people during the 20th century.

The United States was drawn into a war already underway for more than 4 years.

The preliminary planning for Operation Downfall – the invasion of the Japanese home islands of Kyushu and Honshu – began in the waning months of 1944. These were preliminary plans at best and were secondary to battle planning for Leyte, Luzon, Iwo Jima, Okinawa and the naval aircraft carrier raids on Formosa, as well as the massive logistics planning to support all the amphibious landings.

By April 1945 only the amphibious landings at Okinawa remained – the other islands had been secured, although scattered actions continued on Luzon until the end of the war. It was at this point that area commanders (Nimitz and McArthur) were ordered to develop detailed, actionable plans for the invasion of the southern island of Kyushu (Operation Olympic). As noted in the previous post there were multiple planning units that were providing estimates. The operations and logistics details were massive, but each unit knew the “hard question” would be their estimates of allied casualties for Operation Olympic. 

But that question depended on their battle plan/order of battle and intelligence estimates of enemy troop strength and deployment. As will be made clear in subsequent posts, all the above was a moving target that was being shaped by a range of factors from the concrete and measurable to the personal and not quantifiable. The first phase of planning occurred in the Pacific theatre of operation from Nimitz’s and MacArthur’s operations group. This planning phase (and its iterations) lasted until May 25, 1945 at which point the Joint Chiefs of Staff (JCS) issued a formal directive to Nimitz, MacArthur, and Arnold, instructing them to begin detailed planning for Operation Olympic. We’ll come back to that date.

It is time to introduce the key figures “behind the curtain” of the United States. Apart from the human and political intrigue native to any human enterprise, the chain of command was clear. In wartime, the President of the United States was the “Commander in Chief.” He possessed the unilateral power to make decisions, was active in soliciting discussion, and most often took the advice of his military leaders. But it was clear that the “buck” stopped on the desk of the President.

The American operational leadership of the Asia-Pacific war effort was established and consistent from the inception of war to its conclusion in 1945. 

We jump ahead on the timeline for a moment to complete the Allied thought that began at the  Jan 1943 Casablanca Conference: terms of surrender for Germany and Japan. 2.5 years after Casablanca, after Nazi Germany had unconditionally surrendered, the Allies prosecuting the war in the Pacific met. On July 26, 1945, US President Harry S. Truman, UK Prime Minister Winston Churchill, and President of China Chiang Kai-shek issued a document, which outlined the terms of surrender for the Empire of Japan. The Potsdam Declaration (Proclamation Defining Terms for Japanese Surrender) was a statement that called for the surrender of all Japanese armed forces. The ultimatum (and it was worded as an ultimatum) warned: “We will not deviate from them. There are no alternatives. We shall brook no delay.” The ultimatum was clear: if Japan did not unconditionally surrender, it would face “prompt and utter destruction.” By this time in the war Japan was already devastated by bombing and only possessed defensive capability. The war was all but lost by any conventional standard. The Potsdam statement was released only 11 days before the atomic bombing of Hiroshima.

Who were the allied leaders whose decisions would be the most impactful on the Asia- Pacific War? And equally important what were key inter-allied conversations and decisions that would shape the manner and outcome of the war?  Unlike Japan that had no effective dialog or connection to its Axis partners, the Allied met quite regularly in high level conferences with its partners. Quite early in the war, the allies agreed that both the war in Europe and the Asia-Pacific would end in unconditional surrender.

At the January 1943 Casablanca Conference the Allies (U.S., Britain, USSR*) demanded, as pertains to Japan, that Japan surrender without preconditions, meaning:

• total disarmament,
• Allied occupation of the home islands,
• war crimes trials, and
• Reshaping of Japan’s government along democratic lines.

At no point did the policy mention the future of the Emperor, a central figure in Japan’s political and spiritual life.

This policy did not emerge from a vacuum but was rooted in and shaped by the experience of World War I, current knowledge of WWII axis war crimes, and concerns over postwar stability.