The military implications of Chinese control of Taiwan are understudied. Chinese control of Taiwan would likely improve the military balance in China's favor because of reunification's positive impact on Chinese submarine warfare and ocean surveillance capabilities. Basing Chinese submarine warfare assets on Taiwan would increase the vulnerability of U.S. surface forces to attack during a crisis, reduce the attrition rate of Chinese submarines during a war, and likely increase the number of submarine attack opportunities against U.S. surface combatants. Furthermore, placing hydrophone arrays off Taiwan's coasts for ocean surveillance would forge a critical missing link in China's kill chain for long-range attacks. This outcome could push the United States toward anti-satellite warfare that it might otherwise avoid, or it could force the U.S. Navy into narrower parts of the Philippine Sea. Finally, over the long term, if China were to develop a large fleet of truly quiet nuclear attack submarines and ballistic missile submarines, basing them on Taiwan would provide it with additional advantages. Specifically, such basing would enable China to both threaten Northeast Asian sea lanes of communication and strengthen its sea-based nuclear deterrent in ways that it is otherwise unlikely to be able to do. These findings have important implications for U.S. operational planning, policy, and grand strategy.