Russia’s brutal war on Ukraine is, most observers agree, an assault on democracy, sovereignty and human rights.

For the United States and its NATO allies, the Kremlin’s aggression demands a powerful response, including unprecedented economic sanctions against Russia and huge amounts of military aid to Ukraine. But the West will stop short of any direct intervention, lest it be viewed as a declaration of war against Russia.

The contours of America’s policy toward Taiwan remain far less clear. And that is precisely the point: by refusing to say whether it would defend Taiwan against a Chinese invasion, the U.S. has helped to deter China — which does not want to risk a war with the world’s leading military superpower — without making any promises it might not want to keep. The question is whether this policy of “strategic ambiguity” can offer Taiwan the kind of protection that Ukraine clearly lacked.