Deterrence depends on Beijing

Chinese President Xi Jinping’s (習近平) departure from the US gave Taiwan some reason for relief. Despite his unusually warm welcome for Xi, US President Donald Trump avoided an off-the-cuff statement that could be interpreted as a major change in US policy toward Taiwan.

Although there is no evidence that Trump has decided to abandon Taiwan, Beijing might conclude that the US’ resolve has weakened.

Deterrence rests on three elements: capability, resolve and perception. The US must have the capability to intervene, the political resolve to bear the costs and, crucially, convince Beijing that both are credible.

Taiwanese frequently ask whether the US would defend Taiwan. The more important strategic question is: Does Xi believe that it would?

Suppose Beijing once considered US intervention highly likely, but political signals cause it to revise that estimate downward. Not a single US aircraft carrier needs to leave the Pacific. US military capabilities could remain unchanged while Beijing’s expected cost of attacking Taiwan declines. Deterrence could weaken without any formal change in US policy.

That is why Trump’s hospitality toward Xi deserves attention. It would be simplistic to interpret it as evidence that Trump is “pro-China” or preparing to abandon Taiwan. The more consequential question is how Beijing interprets the signal.

Trump might believe that cultivating a strong personal relationship with Xi reduces tensions and therefore the risk of war.

Xi could reach a different conclusion: Trump values his relationship with Xi and stable US-China relations so highly that he might hesitate to sacrifice them over Taiwan.

In deterrence, the sender does not control how a signal is received. Wars can begin because leaders underestimate an adversary’s willingness to resist.

That is the kind of miscalculation Taiwan must prevent.

An additional dimension of deterrence is political endurance.

A Taiwan conflict could produce substantial US casualties, losses of major military assets, disruption of semiconductor production, severe global economic damage and escalation between two nuclear powers.

Xi must calculate not only US military capability, but whether a US president, the US Congress and the US public would continue to support a conflict after those costs became real.

Military power tells an adversary what a country can do. Resolve tells it what the country is willing to do. Political endurance tells it how much pain the country will absorb before changing course.

Competition can strengthen deterrence. US deployments in the Indo-Pacific region, arms sales to Taiwan and closer cooperation with Japan and the Philippines can raise the expected costs of Chinese aggression.

However, great-power competition can also coexist with great-power accommodation.

If Beijing concludes that Washington increasingly values a stable relationship with China — and fears jeopardizing that relationship over Taiwan — increased US-China competition alone will not guarantee Taiwan’s security, so it cannot outsource its deterrence entirely to Washington.

US support remains indispensable, but Taiwan’s defense strategy must remain credible even under uncertainty about US intervention.

That means asymmetric weapons, drones, anti-ship missiles, mines, air defense, resilient communications and energy infrastructure, effective reserve mobilization and, ultimately, a demonstrated political willingness to resist.

Xi should remain uncertain whether the US would intervene, and even if Washington did not intervene immediately, Xi should remain uncertain whether China could conquer Taiwan quickly and at an acceptable cost.

Taiwan has limited control over the first calculation, but far greater control over the second.

Trump’s restraint during Xi’s visit provides some reason for relief, but the lavish reception also makes the next signals from Washington especially important. Arms sales, force posture, alliance coordination and responses to Chinese coercion will matter far more than diplomatic ceremony in shaping Beijing’s assessment of the US’ resolve.

The most important question is what Xi believes Trump will do for Taiwan when the costs become real.

Simon H. Tang is an adjunct professor at California State University, Fullerton, who lectures on international relations.