Taiwan has been enmeshed in United States foreign policy for the last six and a half decades. It is a complex issue that is often a point of key contention in U.S.-China relations. What role Taiwan plays and the impact that follows has varied greatly over time, as has its impact on U.S.-China relations, for good or ill. The level of tensions has ebbed and flowed, along with the various factors at play, but the key factor has always been the degree of enmity between Beijing and Taipei. A high level of tension entails the risk of wider conflict that might draw in the United States and leads each side to enlist Washington support.