Confounding expectations, Taiwan reduced its military spending for many years even as its sole adversary, the People's Republic of China, modernized its military and significantly increased its defense budget. Michael Chase examines the key factors that have shaped Taiwan's security policy over a span of three decades. Chase explores both the role of US security assurances in formulating Taiwan's defense policy and the profound influence that domestic politics has played. He also considers the context of cross-Strait relations and the implications of Taiwan's security choices for potential instability and conflict in the region and beyond. Relying on extensive Chinese-language sources and interviews, he offers the most definitive treatment of Taiwan's security policy to date.