Taiwan holds largest ever exercise to stop an invasion from China

Taiwan just launched its largest-ever annual military drill, the Han Kuang exercise, simulating a full-scale defense against a Chinese invasion. Now in its 41st year, the 10-day event mobilized more than 22,000 reservists and featured U.S.-made HIMARS rocket launchers for the first time. Soldiers rehearsed urban defense operations, made use of the Taipei Metro for tactical mobility and repurposed schools as command posts.

The drills began with a simulated “gray zone” cyberattack that took out Taiwan’s central command. It’s a realistic scenario many experts believe would mark the early phase of a Chinese assault. The term “gray zone” refers to high-intensity, non-kinetic tactics, such as misinformation campaigns and cyberwarfare, that blur the line between peace and conflict.

Taiwanese defense officials said they are applying lessons from the war in Ukraine to improve their readiness. One senior official said commanders were urged to “think realistically about what Taiwan might face in real combat,” especially in the event of a communications blackout.

In the shadow of the ‘Davidson Window’

The exercise is taking place as an inauspicious deadline known as the “Davidson Window” fast approaches. The term was coined by former U.S. Indo-Pacific Commander Admiral Philip Davidson as a prediction that China will likely attempt to invade Taiwan by 2027 or 2028. That timeline is now a strategic benchmark for Taiwan, the United States and its allies in the region.

Taiwan’s government, led by President Lai Ching-te, firmly rejects Beijing’s sovereignty claims and insists the future of the island must be decided by its people. Yet the Chinese Communist Party maintains Taiwan is a breakaway province, and Beijing has not ruled out using military force to bring it under control.

In response to the drills, China’s Foreign Ministry condemned Taiwan’s reliance on U.S. support, calling the exercises a “bluff” and warning that “Taiwan can’t resist the People’s Liberation Army’s sharp sword.” The PLA continues to conduct near-daily military operations around the island, increasing pressure and eroding Taiwan’s defensive margins.

US support: Strategic or symbolic?

Despite the high stakes, one critical element was again missing from this year’s Han Kuang: U.S. military participation.

Under the U.S. policy of “strategic ambiguity,” Washington is committed by law to help Taiwan defend itself, but it stops short of guaranteeing direct military intervention. This murky stance is one of the reasons why American and Taiwanese forces do not conduct joint military drills, which is a notable departure from standard U.S. military practice with regional allies like Japan and the Philippines.

Experts say that absence poses a strategic risk. Without bilateral training, the two militaries may lack the interoperability needed to function as a unified fighting force in the event of a Chinese invasion. In an article from National Defense Magazine, Mark Montgomery of the Foundation for Defense of Democracies warned if war breaks out, American and Taiwanese forces would be “de-conflicted at best,” far from the kind of integrated coalition seen in other theaters.

The high cost of not rehearsing

Based on previous reporting from Straight Arrow News, U.S. involvement in Taiwan’s defense (should it happen) would likely rely on long-range strikes from bombers, submarines and ground-based launchers. The American military may also unleash a flood of autonomous systems in a campaign known as Project Hellscape. But none of that works optimally without prior coordination.

Bryan Clark, director at the Hudson Institute’s Center for Defense Concepts and Technology, put it bluntly: “If it’s a mess because it’s not well coordinated, then China might just be able to get enough troops ashore to succeed.” Without joint drills, the U.S. could find itself fighting over contested skies and seas with devastating losses in ships, aircraft and lives.

Can this year’s drills change US policy?

There are signs the tide could be shifting. Experts believe the scale and realism of this year’s Han Kuang exercise may influence future U.S. decisions.

Still, time is short. Even if the United States were to reverse course tomorrow and begin conducting joint drills with Taiwan, there would be precious little time to build true operational synergy before the Davidson Window closes.

Han Kuang 2025 has been Taiwan’s boldest signal yet that it is preparing to fight for its sovereignty. But without U.S. forces side-by-side on the battlefield — even in simulation — the effectiveness of that fight remains in doubt.