US-China Military Standoff in the South China

📡 The Signal — What Happened

Why it matters: In early 2026, simultaneous US and Chinese military exercises in the South China Sea have pushed the risk of accidental collision to its highest level since the Cold War. This tension could become a structural turning point, shaking the foundations of security for Japan, Taiwan, and ASEAN nations, and the global economy.

• Military — From January to March 2026, the US Navy conducted "Freedom of Navigation Operations" (FONOPs) in the South China Sea at a record pace of more than three times a month, deploying two carrier strike groups simultaneously.
• Military — The Chinese People's Liberation Army Navy (PLAN) conducted large-scale live-fire exercises across the South China Sea in February 2026, expanding the exercise area further south than before.
• Diplomacy — The US State Department reiterated its condemnation of China's territorial claims based on the nine-dash line as "violations of international law" and issued a statement strengthening security cooperation with the Philippines and Vietnam.
• Diplomacy — The Chinese Ministry of Foreign Affairs criticized the strengthening of the US military presence in the South China Sea as "provocative acts that undermine regional peace and stability" and hinted at countermeasures.
• Incident — In late February 2026, an incident occurred near Scarborough Shoal where a US destroyer and a Chinese naval frigate approached within approximately 45 meters of each other.
• Economy — The South China Sea is the most critical sea lane, through which approximately one-third of global trade (worth about $5.3 trillion annually) passes, and rising conflict risk directly impacts insurance premiums and shipping costs.
• Alliance — Japan achieved approximately 2% of GDP in its 2026 defense budget, deciding to strengthen the defense of the Nansei Islands and increase the frequency of Japan-US joint exercises.
• Alliance — The Philippines expanded the number of EDCA (Enhanced Defense Cooperation Agreement) sites to nine under the US-Philippines Mutual Defense Treaty, accepting rotational deployment of US forces in the South China Sea.
• Technology — China completed the deployment of HQ-9B long-range surface-to-air missiles and YJ-62 anti-ship missiles on its artificial islands in the Spratly Islands, enhancing its A2/AD (Anti-Access/Area Denial) capabilities.
• International Law — The 2016 Permanent Court of Arbitration ruling rejected China's nine-dash line claims, but China has consistently rejected the ruling as "a piece of paper."
• Domestic Politics — 2026 is a US midterm election year, and the Biden administration (or its successor) has extremely limited room to soften its hardline stance on China domestically.
• Resources — The South China Sea is estimated to hold 11 billion barrels of oil and 190 trillion cubic feet of natural gas, with the competition for resources complicating territorial disputes.

To understand the current escalation of US-China confrontation in the South China Sea, it is necessary to trace at least three historical trends.

First, there is the lineage of China's "maritime power" strategy. Since the inauguration of the Xi Jinping administration in 2012, China has made the expansion of maritime interests a core national strategy as part of the "great rejuvenation of the Chinese nation." From 2013 to 2015, it constructed seven artificial islands in the Spratly Islands, successively developing runways, radar facilities, and missile sites. This marked a clear departure from Deng Xiaoping's "hide your strength, bide your time" (韜光養晦) approach and was the culmination of China's "salami-slicing" strategy to create faits accomplis in its sphere of influence. Even after the 2016 Hague arbitration ruling rejected the nine-dash line, China completely ignored it, instead accelerating militarization. This series of actions decisively heightened the vigilance of the United States and its allies as a challenge to the rules-based international order.

Second, there is the evolution of the US Indo-Pacific strategy. The Obama administration's "rebalance to Asia" policy was an attempt to shift the US strategic center of gravity from the Middle East to the Asia-Pacific, but it was not fully implemented due to the Syrian civil war and the Ukraine crisis. The first Trump administration championed a "Free and Open Indo-Pacific (FOIP)" and clearly defined competition with China. The Biden administration inherited and expanded this, building a multi-layered security network surrounding China, including AUKUS (Australia-UK-US security partnership), the institutionalization of the Quad (Japan, US, Australia, India), and the expansion of EDCA with the Philippines. Even after the inauguration of the second Trump administration in 2025, the hardline stance on China has been maintained as a bipartisan consensus. The South China Sea is the frontline of this strategic competition, and US FONOPs (Freedom of Navigation Operations) have become a symbol of US hegemonic presence, beyond mere adherence to international law.

Third, there is a structural shift in the regional order. ASEAN (Association of Southeast Asian Nations) has traditionally functioned as a balancer between great powers, but in the South China Sea issue, the interests of member states are divided. The Philippines and Vietnam have direct territorial disputes with China and are strengthening security cooperation with the United States. Meanwhile, Cambodia and Laos are under China's economic influence, hindering the formation of a unified ASEAN stance against China. This "alliance strain" gives China room for divide and conquer tactics, weakening the region's collective security mechanisms.

What makes the situation in early 2026 particularly dangerous is the simultaneous interplay of multiple structural factors. First, although military hotlines and risk management mechanisms between the US and China have partially recovered since 2023, confidence-building at the operational level remains insufficient. Second, the interconnectedness between the Taiwan issue and the South China Sea issue is increasing, raising the risk of a "chain of contagion" where tensions in one area escalate in the other. Third, the deployment of AI-powered drones and autonomous weapon systems is progressing, making scenarios of accidental collisions without human intervention more realistic. Fourth, the US domestic political cycle (2026 midterm elections) makes any softening of the hardline stance on China politically impossible.

These factors combine, and the South China Sea is falling into a self-reinforcing dynamic of a "spiral of conflict." This is a vicious cycle where one side's military actions provoke countermeasures from the other, leading to further escalation. Unlike the US-Soviet confrontation during the Cold War, there are no established implicit rules based on nuclear deterrence balance between the US and China, and "gray zone" incidents at the conventional force level pose the greatest challenge to escalation management.

The delta: In early 2026, the US-China military confrontation in the South China Sea entered a new phase, both quantitatively and qualitatively. The increased frequency of US FONOPs and simultaneous deployment of carrier strike groups, combined with China's completion of missile deployments on artificial islands and expansion of exercise areas, pushed the risk of accidental collision to its highest level since the Cold War. The incident of an abnormal approach within 45 meters exposed the fragility of escalation management mechanisms. What has decisively changed is that both sides are becoming entrenched in a structure where they "cannot back down."