Signaling, interests, and domestic politics: What matters for US credibility in Taiwan

There have been growing calls for a rethink of U.S. policy towards Taiwan. Some argue that the U.S. should signal stronger commitment to Taiwan to deter China and maintain peace. To do so, a growing number of commentators and policymakers advocate that the U.S. provide a clear security guarantee to Taiwan. Others have suggested deploying troops on Taiwanese soil again. These calls beg an empirical question, one central to the study of international politics: how much would such reassurance measures increase confidence that one country would defend another if attacked? We find that an alliance with the U.S. and the deployment of troops on Taiwan would meaningfully increase confidence in the U.S. even when controlling for other factors. By estimating the magnitude of the effect of other variables cited in the literature, we also contribute to the ongoing debate over their relative influence on credibility. Specifically, our evidence suggests that the perceived alignment of interests is the cornerstone of credibility. The degree of division in the domestic politics of the patron state, in this case the U.S., also is a crucial determinant of credibility.