China’s interests in the South China Sea are profoundly commercial and economic, not merely military or nationalist. The sea functions as one of the central arteries of China’s economy and global position. Beijing views control, influence, or at least secure access to the region as vital to national survival and long-term development.

The South China Sea as a Strategic Economic Corridor. Roughly one-third of global maritime trade passes through the South China Sea (SCS), including enormous volumes of container shipping, energy imports, bulk commodities, and manufactured exports. For China specifically, the sea links China’s industrial east coast, Southeast Asian markets, the Indian Ocean, the Middle East, Europe, Africa and the United States. Chinese ports such as Port of Shanghai, Port of Shenzhen, and Port of Guangzhou depend heavily on uninterrupted maritime access through these waters. A disruption in the SCS could severely affect the exports of Chinese manufactured goods, imports of raw materials, and China’s supply chains.

Maritime trade in the South China Sea can be described by any number of measures. Its importance can be measured in a variety of ways: total trade value, shipping volume, energy flows, container traffic, and its role in global supply chains. The most widely cited estimate is that roughly $3–5 trillion in global trade passes through the SCS annually. That represents approximately 25% of global marine trade. Roughly one-third of global maritime crude oil trade passes through these waters. East Asia is the manufacturing center of the global economy and the SCS is central to containerized trade. Major shipping companies route vessels through the SCS because it is the shortest and most efficient path from manufacturing centers to delivery ports abroad. 

China’s economy is particularly dependent on these routes because China is the world’s largest exporter, it imports massive energy supplies, and much of its coastal industrial economy faces the South China Sea. Chinese strategic planners worry about blockade risks, foreign naval control, and vulnerability at maritime chokepoints – especially the Malacca Straits, the southwest entrance to the South China Sea.

Energy Security: Oil and LNG Imports. One of China’s greatest vulnerabilities is energy dependence. China imports massive amounts of crude oil, liquefied natural gas (LNG), and other energy products from the Persian Gulf, Africa, and elsewhere in the Indian Ocean region. Much of this energy passes through the Strait of Malacca, then across the South China Sea, and onward to Chinese ports. Chinese strategists often refer to this vulnerability as the “Malacca Dilemma,” the fear that in a crisis, especially involving the United States, these sea lanes could be interdicted or blockaded. This concern drives several Chinese policies including naval modernization, artificial island construction, maritime patrol expansion, diversification of pipelines, and the Belt and Road Initiative.

Oil and Gas Resources Within the South China Sea. The South China Sea itself is believed to contain significant oil reserves, very large natural gas reserves, and rich seabed resources. Estimates vary widely because much of the region remains underexplored, but China sees these potential reserves as strategically important. China’s state energy firms, including China National Offshore Oil Corporation (CNOOC), have pursued offshore drilling, seismic surveys, and joint development proposals. Disputes emerge because Vietnam, the Philippines, Malaysia, and Brunei also claim many of the same waters and offshore blocks.

Fisheries and Food Security

The South China Sea contains some of the world’s richest fishing grounds. Fish are commercially important to China because seafood demand is enormous, coastal populations have long depended on fishing, and food security remains a strategic concern. Chinese fishing fleets operate extensively in disputed waters. Fishing vessels also serve secondary purposes: reinforcing Chinese presence, supporting maritime claims, and sometimes operating alongside the Chinese maritime militia.

Precise estimates of annual fish extraction are difficult because the SCS is heavily overfished, illegal and unreported fishing is widespread, and countries often underreport or distort catch data. Some estimates suggest over half the world’s fishing vessels operate in the broader South China Sea region. But the best academic and fisheries reconstructions provide reasonably credible estimates.  Most estimates center on 10 million metric tons per year of fish caught in the SCS. China is estimated to take 35-50% of the total catch which is not surprising since China possesses (by far) the world’s largest fishing fleet, including coastal fleets, distant-water fleets, and maritime militia-associated vessels. 

China is the world’s largest seafood consumer and growing middle-class demand has intensified fishing pressure. It must also be remembered that fishing activity is not only economic, but reinforces maritime claims, presence around disputed reefs, and gray-zone operations. As such, the Chinese fishing fleet is highly subsidized because of its importance to China’s economy. 

Fish are not a marginal issue in the SCS dispute. For China, fisheries involve food security, employment, maritime sovereignty claims, and regional influence. Some analysts argue that fisheries are one of the most immediate drivers of day-to-day confrontation in disputed waters – more so than oil. This is because studies indicate fish stocks in the SCS have declined by 70–95% since the 1950s, catch rates have fallen dramatically, and fleets increasingly catch smaller and younger fish lower on the food chain. China and bordering nations, all of which historically and culturally have fish as a major source of dietary protein, are chasing an increasingly diminishing commodity.

China has been aggressively intruding into waters and maritime zones that the Philippines claims under international law, particularly within the Philippine Exclusive Economic Zone (EEZ) in the SCS. Much of the friction occurs in waters west of the Philippine island of Palawan, especially around Second Thomas Shoal, Scarborough Shoal, Mischief Reef and Reed Bank. These areas fall within 200 nautical miles of the Philippines and are therefore claimed by Manila as part of its EEZ under the United Nations Convention on the Law of the Sea. Philippine fishermen have repeatedly reported being blocked from traditional fishing grounds, harassment by Chinese coast guard vessels (which are armed with 5-inch guns and automatic weapons), water cannon incidents, confiscation of catches, and dangerous maneuvering at sea. China coast guard and maritime militia vessels are constructed with reinforced bows capable of – not full on ramming – but shall we say quite aggressive nudging.

Maritime militia vessels disguised as fishing boats and PLA Coast Guard vessels are used to assert Chinese claims, maintain constant presence, pressure rival claimants, while avoiding overt naval warfare. The Philippines and its allies characterize many of these tactics as “gray-zone coercion,” aggressive pressure below the threshold of armed conflict.

Trade With Southeast Asia. The South China Sea is also the maritime bridge connecting China to the Association of Southeast Asian Nations (ASEAN) economies. ASEAN is one of China’s largest trading partners accounting for 20% of trade with China. Goods moving through the region include electronics, machinery, semiconductors, consumer goods, agricultural commodities, and industrial inputs. Any instability in these waters threatens Chinese exports, regional manufacturing networks, and supply-chain integration.

Undersea Infrastructure and Communications. Less visible but increasingly important are submarine communication cables, offshore infrastructure, and digital trade routes. The South China Sea contains major undersea fiber-optic cable systems connecting East Asia to the broader world economy. Control or monitoring of maritime zones can therefore have implications beyond shipping to include telecommunications, internet traffic, financial systems, and digital commerce.

The SCS marine floor has the highest concentration of marine fiber optic cables. These cables carry financial transactions, cloud computing traffic, military communications, commercial internet traffic, and industrial data. For China, they support export industries, global manufacturing networks, e-commerce, artificial intelligence infrastructure, and digital connectivity under the Belt and Road Initiative.  The SCS infrastructure forms the hub that connects China and East Asia with Singapore, India, the Middle East, Europe, and Africa. It is part of China’s “Digital Silk Road” initiative.

The geography of the SCS makes it difficult to avoid. Nearly all East Asian digital traffic heading westward toward Europe or the Indian Ocean passes through cables in these waters. This creates both opportunity and vulnerability for China. Chinese strategists worry about cable sabotage, surveillance, bottlenecks, and wartime disruption. As a result, China has pursued redundant cable routes, alternate land corridors, and Arctic communications concepts, yet 95% of China’s extra-territorial communication still passes through these cables.

Strategic Economic Buffering. China’s island-building campaign has economic as well as military dimensions. Artificial islands allow China to support coast guard and maritime enforcement activity, monitor shipping, sustain fishing fleets, protect energy exploration, and reinforce administrative control over contested waters. Beijing argues these activities secure lawful commercial interests; critics view them as coercive attempts to dominate international waters.

The Broader Chinese Perspective. From Beijing’s viewpoint, the South China Sea is not a distant frontier. It is viewed as 

• a near-seas defensive zone,
• an economic and food security lifeline,
• an energy transit corridor,
• and a gateway to China’s continued rise as a global power.

Many Chinese strategists believe that if hostile powers controlled these waters, China’s economy, trade, energy supply, and geopolitical autonomy could all be placed at risk. That perception helps explain why the South China Sea occupies such a central place in Chinese national strategy even beyond the military dimension.

The Nine-Dash Line

The “Nine-Dash Line” is a map boundary used by the People’s Republic of China to claim large portions of the South China Sea. It is not directly a sovereignty claim over Taiwan, but it is closely connected to the broader China–Taiwan issue because both the government in People’s Republic of China (Beijing/PRC) and the government in Taiwan (the Republic of China, or ROC) historically inherited versions of the same maritime claims from pre-1949 China. But they are not the only countries with claims in the South China Sea. Claimants include Vietnam, Malaysia, Indonesia, Singapore, Brunei and the Philippines.

The line originated with the Republic of China government in 1947 as an “Eleven-Dash Line.” After the Chinese Civil War, the communist government in Beijing adopted and modified it into the current Nine-Dash Line. Taiwan’s ROC government still officially maintains a similar claim, though Taipei today emphasizes stability and practical administration more than expansive maritime nationalism. It is interesting to note that Beijing sometimes argues that Taiwan’s continued adherence to similar maritime claims supports the idea that both sides belong to “one China.”

The Nine-Dash Line matters because the South China Sea contains major international shipping lanes, commercial fishing grounds, potential oil and gas reserves and militarily is a key strategic location. PRC/China has used the claim to justify building shoals into artificial islands, establishing military facilities there and on naturally existing islands, as well as conducting aggressive coast guard and naval patrols. Reports and videos of aggressive  maritime engagements routinely appear online, in the news, and in maritime industry journals.

The Nine-Dash Line, in a way, is tangential to the China-Taiwan dispute. The Nine-Dash Line is primarily a South China Sea territorial claim, not a direct claim about Taiwan itself. However, it is important as Taiwan controls Taiping Island (Itu Aba), the largest naturally occurring island in the Spratly chain – and some 1,000 miles south-southwest of Taiwan. This gives Taiwan a direct physical role in South China Sea disputes. Taiwan also sits near the northern gateway to the South China Sea from the East China Sea and along critical naval routes connecting the Pacific Ocean to Chinese coastal waters. 

But the nations most impacted by aggressive PRC maritime patrols and attempts at enforcement are the Philippines, Malaysia, Vietnam and Indonesia. The South China Sea is important to these nations for the same reasons it is economically important to China.

Claims and Assertions

The origin of the “Nine-Dash Line” is rooted in a mixture of historical memory, nationalism, geography, imperial legacy, and modern state-building. It was not created out of nowhere as a purely arbitrary assertion, but neither was it historically defined in the precise modern legal sense that China sometimes presents today.

Chinese dynastic records from the Song, Yuan, Ming, and Qing periods contain references to islands, shoals, navigation routes, and fishing grounds in what is now called the South China Sea. For centuries, Chinese fishermen, merchants, and sailors traveled through the South China Sea. Chinese fishermen from Hainan and Guangdong regularly traveled seasonally into the Paracel and Spratly regions. Chinese sources also describe maritime trade routes through the area. Imperial Chinese records, navigation charts, and local gazetteers mention these areas intermittently. China argues that these activities demonstrate discovery and naming of islands, longstanding fishing usage, patrols and survey expeditions, and administrative awareness of the region. There is also archaeological evidence of extensive Chinese commercial activity seen in shipwrecks, porcelain cargoes, copper coins, and evidence of the old Maritime Silk Road crossing the South China Sea.

But the South China Sea was never an exclusively Chinese maritime zone historically. Vietnamese, Malay, Filipino, and other Southeast Asian fishermen and traders also operated throughout the region for centuries and can make the same historical and archaeological claims. Even some Chinese legal scholars acknowledge the sea historically functioned as a shared maritime space used by many peoples.

What’s more, pre-modern Asian states generally did not define maritime sovereignty the way modern international law does. It was understood that “control” was fluid and shifting as seen in tribute systems, fishing access, trade routes, or occasional patrols rather than fixed maritime borders. So there was a historical Chinese presence and awareness in the region, but not continuous modern-style administrative control over the entire sea. The same can be said about several other nations.

This is important because under modern international law, merely having fishermen or traders present does not automatically create sovereignty over enormous maritime areas.

The Modern Era

The 1947 assertion by the Republic of China government under the Kuomintang (still before the takeover by the Communist Chinese) reflected several motivations. It was reclaiming territory after Japanese occupation, asserting China’s status as a restored great power, resisting perceived Western and Japanese encroachment, and strengthening national unity after decades of invasion and civil war. When the communists won the Chinese Civil War in 1949, the government in Beijing took up the mantle of maritime claims.

For many Chinese people both in mainland China and Taiwan, the South China Sea claims became emotionally tied to the broader narrative of overcoming the “Century of Humiliation.” That narrative includes the Opium Wars, the Unequal Treaties that resulted from those wars, the resulting colonial concessions, the Japanese invasion, and the loss of sense from the foreign domination that was in place from the 19th to mid-20th centuries. In this mindset, recovering lost territories became symbolic of restoring national dignity and sovereignty. Many Chinese see the South China Sea claims not as expansionism, but as reversing historical injustice. But the counter-claimants in the region are not nations or peoples involved in any historical injustices against China.  The controversy is that historical usage, shifting periods of colonial dominance, and other factors are not automatically factors in modern legal sovereignty under international law. 

In 2016, an international tribunal in The Hague ruled in a case brought by the Philippines that China’s sweeping Nine-Dash Line claims had no legal basis under the UN Convention on the Law of the Sea (UNCLOS). Beijing rejected the ruling. Taiwan also rejected parts of the decision because it affected claims tied to Taiping Island.

South China Claims and Economic Zone Disputes

The relationship between mainland China and the island known today as Taiwan has evolved over many centuries and is shaped by migration, imperial rule, colonialism, civil war, competing national identities, and modern geopolitics. The history is complex because both the mainland government of the People’s Republic of China (PRC) and the government of Taiwan, the Republic of China (ROC), developed different interpretations of sovereignty and legitimacy.

Early Taiwan Before Large-Scale Chinese Settlement. For thousands of years, Taiwan was inhabited by Austronesian Indigenous peoples, culturally and linguistically related to peoples in the Philippines and Pacific islands. Imperial Chinese dynasties knew of the island, but for much of history it remained outside direct Chinese administration. Beginning in the late Ming period (16th–17th centuries), increasing numbers of settlers from Fujian and Guangdong provinces migrated to Taiwan, especially fishermen and farmers.

European Colonial Presence (1600s). In the early 17th century, European powers entered Taiwan. The Netherlands established a colony in southern Taiwan in 1624. Then Spain briefly occupied northern Taiwan from 1626–1642. There is much that can be said about this period but there is perhaps one lasting effect: the Dutch encouraged Han Chinese immigration to develop agriculture and trade. The indigenous people identity was, for all practical purposes, at risk of being absorbed into a Chinese identity.

Taiwan apart from China. In the 17th century the Ming Dynasty of China fell to the Qing Dynasty. In 1662, a Ming loyalist on Taiwan, Zheng Chenggong (Koxinga), expelled the Dutch and established a regime on Taiwan. It was an outpost of the now fallen Ming Dynasty. Koxinga hoped Taiwan could serve as a base to retake mainland China from the Qing. Even from this early date there was a strong sense of “other” from the mainland Chinese. This and the following years are a fluid time in the history of China, Japan and Korea.

Qing Dynasty Comes to Taiwan. In 1683, the Qing conquered Taiwan and incorporated it into the empire. Initially the Qing treated Taiwan as a frontier territory and limited migration, but over time millions of Han Chinese settlers arrived. During this period indigenous peoples were gradually displaced from western plains into mountainous regions, ethnic tensions sometimes emerged between settlers from different regions of China, and Taiwan became increasingly linked economically and culturally with the mainland Fujian province. In 1885 Taiwan became a full province of the Qing Empire and firmly part of mainland China. The Chinese Qing government was China’s last imperial dynasty. 

But by this time the Qing Empire had fallen on hard times at the hands of the European colonial powers, especially Britain. The great lure of China had not only been for its exotic exports but the possibilities of exports to China with their population in the millions. In the mid-19th century Britain had a massive trade deficit with China, as they imported huge amounts of tea, silk, and porcelain but China wanted few British products in return. An import/product was needed that would balance the trade relationship. Unfortunately the British East India company began the importation of opium from India. It became the commodity that reversed the cash flow, paying for Chinese goods but causing widespread addiction in China.

Seeing the social and economic devastation, the Qings banned opium in 1839. They confiscated and destroyed over 20,000 chests of British opium in Guangzhou (Canton), the merchants demanded compensation, viewing it as an attack on property. Their demand was backed by the British government who further demanded “free trade” and an end to China’s restrictive Canton system which limited each foreign nation’s traders to one port and imposed strict rules for transactions. The conflict was fundamentally about sovereignty – China asserting its right to control its own internal affairs versus Britain’s assertion of international trade rights and extraterritoriality for its citizens. The First Opium War between Great Britain and China was fought from 1839 to 1842. The British crushed the Chinese and forced trade agreements that highly favored the British. Other colonial powers demanded equal benefits leading to what are called, “The Unequal Treaties.” A second Opium War was fought in 1857-1858.  

The once great China was now a devastated nation subjected to colonial demands.  Something that was not lost on Japan as it came out of its isolationist period and entered the Meiji Era of Japanese governance. You read about this movement within Japan that would ultimately greatly impact China.

Japanese Rule (1895–1945). The First Sino-Japanese War resulted from the collision of modern Japan’s strategy to be recognized as a great world power, China’s central government declining ability to extract tributes from regions and tribute countries, and increased instability in Korea as Japan and Russia strove to exert influence over this traditional Chinese tribute state. I leave the details of this period and the conflict to others. Japan won and extracted major concessions from China (Treaty of Shimonoseki) one of which was that China transferred full sovereignty of Taiwan (then called Formosa), the Pescadores (Penghu Islands) and the Liaodong Peninsula including Port Arthur, a warm water port. There were many other concessions. For the next 50 years Taiwan was a Japanese colony. Japan built railways, ports, and modern infrastructure; expanded education and public health; suppressed resistance movements; and encouraged Japanese cultural assimilation. The Taiwanese experienced both modernization and colonial subjugation during this 50-year era.

Return to Chinese Rule After World War II.  After World War II, Japan surrendered Taiwan to the Republic of China (ROC) government led by Chiang Kai-shek and the Kuomintang (KMT). However, tensions quickly emerged between local Taiwanese and mainland Chinese administrators. Corruption and economic disruption fueled unrest. In 1947 the February 28 Incident (often called the “2-28 Incident”) erupted after anti-government protests. The KMT violently suppressed the uprising, killing thousands. This became a foundational trauma in modern Taiwanese political memory.

Chinese Civil War and the Division of China (1949). The modern cross-strait conflict largely dates from the end of the mainland Chinese Civil War. In 1949 Mao Zedong and the Chinese Communist Party established the People’s Republic of China (PRC; Communist China) on the mainland. Chiang Kai-shek and the ROC government retreated to Taiwan with roughly 1–2 million soldiers, officials, and refugees. From that point onward the PRC governed mainland China and the ROC governed Taiwan and several nearby islands. Both governments initially claimed to be the sole legitimate government of all China.

The Cold War and Modern Era. During the Cold War the United States supported Taiwan militarily and politically, while the PRC viewed Taiwan as a breakaway province that must eventually be reunified. Major crises occurred in the Taiwan Strait in the 1950s and again in 1995–1996 when missile tests and military exercises heightened tensions.

Taiwan under KMT rule was authoritarian for decades under martial law (1949–1987), a period known as the “White Terror.” Beginning in the late 1980s, Taiwan democratized: martial law ended, opposition parties were legalized, and free elections developed leading to modern Taiwan with its vibrant democratic and economic system.

Changing Identity

A significant development has been the growth of a distinct Taiwanese identity. Many residents now identify primarily as “Taiwanese” rather than “Chinese,” especially younger generations. At the same time, political opinion in Taiwan varies.  Some support eventual reunification with China, some favor maintaining the current ambiguous status, and others support formal independence. Most polling shows strong support for maintaining the current de facto independence without provoking war.

The Current Situation

Today the PRC claims Taiwan as part of China under the “One China” principle while Taiwan operates as a self-governing democracy with its own military, currency, constitution, and elections. Most countries, including the United States, do not formally recognize Taiwan as an independent state, but many maintain unofficial relations with it. The Vatican does recognize Taiwan (ROC) as an independent nation. The PRC has stated it seeks peaceful reunification but has not ruled out force. Taiwan rejects PRC rule under the Communist Party. This issue remains one of the most sensitive geopolitical flashpoints in the world.

Taiwan and the United States

Here in 2026 the relationship between the United States and Taiwan is intentionally close but formally unofficial. Since Washington shifted diplomatic recognition of China from Taiwan/ROC to the People’s Republic of China in 1979, the U.S. has recognized Beijing as the sole legal government of China under its “One China” policy, while simultaneously maintaining extensive political, economic, and military ties with Taiwan.

Politically, the United States supports Taiwan’s democratic system, its participation in international trade and selected international organizations, and the peaceful resolution of disputes. Washington does not officially recognize Taiwan as an independent state, but it strongly opposes any attempt to change Taiwan’s status by force or coercion. Militarily, the United States is Taiwan’s principal security partner and largest arms supplier. The U.S. is committed to helping Taiwan maintain a sufficient self-defense capability by providing defensive weapons, training, and military support. 

All-in-all, U.S. policy is “strategic ambiguity,” meaning Washington deliberately avoids stating explicitly whether American forces would directly defend Taiwan in the event of a Chinese attack. While supplying Taiwan with arms the U.S. also avoids provoking open conflict with China.