One of the most complicated topics in contemporary international relations is the status of the self-governing island of Taiwan and its government in Taipei, formally called the government of the Republic of China. In this October 9, 2025 talk, Julian Ku, professor of law at Hofstra University, explains what international law says about the use of force for self-defense and collective self-defense in a potential cross-strait conflict, and argues that the United States and Taiwan should prepare credible legal arguments now to rally international support.