Armed Ambiguity in the East China Sea

For decades, American boots have landed on the soil of countries across the globe, deployed out of two of the nation’s greatest regional allies: South Korea and Japan. And, as pressure mounts between China and Taiwan, they could very well be redeployed regionally. Indeed, US Defense Secretary Pete Hegseth confirmed that American forces stationed in the ROK would respond in the event of a Sino military assault on Taiwan. Likewise, even as the US fulfills its legal obligation to lighten its military presence in Japan, its Far East Clause with the nation enables American function out of Japanese facilities to address contingencies in the region—including a Taiwan conflict.

The flexibility of American peacekeeping as the greatest threat to Beijing’s regional hegemony has only expanded as on November 7, Japanese Prime Minister Sanae Takaichi noted that the use of naval military force against Taiwan could lead to a “survival-threatening situation” for Tokyo, implying that the Japan Self-Defense Forces “would be legally allowed to engage in collective self-defense activities in the event of a conflict over Taiwan.” Doing so would enact the 1960 Treaty of Mutual Cooperation and Security, not just allowing American troops to address conflict with Taiwan, but legally obligating the US to engage in a war with Taiwan, Japan and China. Even more concerning, America’s 1953 mutual defense treaty with South Korea could easily pull the ROK as a fifth player into the conflict.

Evidently, the threat of a greatly imbalanced regional conflict wherein democratic powers hold the upper hand geographically and diplomatically creates an immense exigency for Beijing. Consequently, Xi Jinping has increased China’s physical presence in the East China Sea, deploying over 100 naval and coast guard vessels in its largest show of force in East Asia and releasing military planes accused of locking their radar on Japanese fighter jets near the Okinawa islands. According to Tokyo’s Defense Ministry, China’s “active military activities have created a situation that could have a serious impact on Japan’s security.”

Following decades of mounting Sino-Japanese conflict, it’s this threat that appears to have finally pushed Tokyo to significant militaristic modernization. As China’s 2025 defence budget stood at 400% that of Japan’s, Takaichi has begun to eye a 9 trillion yen (57.2 billion dollar) budget increase ahead of 2026. 

Nonetheless, the nation must address China’s ballistic missile threat—with nearly all of which (2,200/3,100) being capable of reaching Japan—to ensure its sovereignty against Beijing. And it’s doing precisely that. In November, Japan’s defense minister Shinjirō Koizumi announced the deployment of Type 03 Chu-SAM surface-to-air missiles on Okinawa Prefecture's Yonaguni Island, just 70 miles from Taiwan. As Newsweek analyzed shortly after, “operated from 8x8 trucks, the Type 03 missile system uses phased-array radar technology to track up to 100 warplanes, ballistic missiles, or drones simultaneously.”

Japanese developments have materialized as a double edged sword, aggravating China to diplomatic aggression. “Japan's deployment of offensive weapons to southwest islands close to China's Taiwan is a deliberate move that creates regional tensions and stokes military rivalry,” Chinese Foreign Ministry spokesperson Mao Ning confirmed.

Following the fortification of the trilateral pact between the US, Japan, and South Korea at the 2023 Camp David Summit, the three aimed to expand Taiwan's defense capability—a commitment Takaichi is, in corroboration with the Trump Administration, only continuing to fortify despite growing diplomatic and physical pressure. Indeed, in early December, the flight of two U.S. B-52 strategic bombers with three Japanese F-35 stealth fighters and three F-15 air-superiority jets marked the first joint military exercise between the two aimed directly at deterring Beijing.

As US Secretary of State Marco Rubio backed by the Trump Administration emphasizes an end to escalation with Taiwan on both fronts and a desire to expand negotiations with the CCP, Takaichi has maintained her position and spread of violently pro-Taiwan remarks. As Japan and China therefore become increasingly aggressive, the United States must establish a position on perhaps what will be one of the defining conflicts of 2026.

Read more here:

• Craig Singleton, The New York Times

• Ju Hyuang Kim, The Diplomat

• Kareem Rifai, The Hill

• Miles Yu, Hudson Institute