Weekly Briefing | East Asia
East Asia is entering a period of growing strategic uncertainty. Rising tensions across the Taiwan Strait, intensifying U.S.-China's competition, North Korea’s nuclear program, and Japan’s military normalization are placing increasing pressure on the region’s security order. For decades, U.S. alliances with Japan and South Korea, alongside support for Taiwan, provided the foundation of regional deterrence. That confidence is now being tested. In August 2026, President Trump directed the Pentagon to scale back the annual Ulchi Freedom Shield exercise, with the Pentagon later confirming that it had “substantially reduced” the exercise. At the same time, Japan and Taiwan are strengthening their own defense capabilities. Together, these developments signal a broader shift: East Asian states are increasingly preparing for a security environment in which American support can no longer be taken for granted.
Washington’s Uncertainty Is Becoming a Security Problem
The reduction of Ulchi Freedom Shield matters because it weakens more than military readiness. It weakens confidence in the alliance itself. Trump’s decision to link military cooperation with Seoul to the Iran war and his relationship with Kim Jong Un demonstrates that U.S. regional commitments can be influenced by priorities far beyond East Asia. The Pentagon’s 2026 National Defense Strategy reinforces this direction by assigning South Korea primary responsibility for deterring North Korea and describing future U.S. support as “critical but more limited”.
Washington has not abandoned East Asia,That is precisely why the current situation is more complicated. The United States remains militarily dominant while its allies face growing uncertainty over whether that power will be available when it matters most. The Iran war has shown how quickly American attention and resources can shift between theaters. Japan, South Korea, and Taiwan must therefore plan not only around what Washington can do, but around what it may choose not to do.
Japan and Taiwan Are Preparing for a Less Certain America
Taiwan is already turning this uncertainty into military policy. Its Ministry of National Defense has confirmed a NT$210 billion special budget for unmanned systems, including coastal surveillance and reconnaissance drones, coastal attack drones, and small one way attack unmanned surface vessels. Defense Minister Wellington Koo has also emphasized reducing dependence on vulnerable foreign supply chains. Taiwan is therefore developing capabilities that it can control and sustain more independently during a crisis.
Japan is following the same direction. Its 2026 Defense White Paper identifies China as an “unprecedented and the greatest strategic challenge” and states that stability across the Taiwan Strait is indispensable to Japan’s security. Japan’s defense expansion is therefore not simply a response to China’s military rise. It also reflects the need to prepare for a regional crisis in which American intervention could be slower, narrower, or less certain than expected.
This creates a dangerous feedback loop. As Washington becomes less predictable, Japan and Taiwan have stronger incentives to expand independent military capabilities. China and North Korea can interpret these capabilities as preparation for confrontation and respond with further military expansion. The region could consequently become more heavily armed while becoming less confident about how a crisis would unfold.
East Asia is not witnessing the end of American power. It is witnessing the decline of confidence in American reliability. The reduction of U.S. South Korean military exercises, competing American wartime priorities, and growing indigenous defense efforts in Taiwan and Japan demonstrate that regional states are already adapting to a less predictable security environment. The central danger is not American withdrawal itself. It is uncertain. When allies cannot confidently determine whether American power will be available during a crisis, they will prepare to act without it. That preparation may strengthen short term deterrence, but it can also accelerate regional militarization and increase the risk of miscalculation. East Asia is therefore moving toward a more autonomous security order, but not necessarily a more stable one.