China has the largest arsenal of missiles with a range of less than 5,500 km. In 2019, the US withdrew from the INF Treaty and decided to deploy the same kind of missiles in East Asia. At the same time Washington plans to strengthen the theater missile defense architecture in the region. The purpose of the article is to determine the potential impact of missile defense strengthening by the US and their partners in East Asia on regional security. It is necessary to understand the prospects of the situation, given the presence of several hotbeds of potential conflict in the Western Pacific. A critical analysis of the expected actions of China and the US in the region, the role of regional missile defense systems in those scenarios, and both sides’ doctrines of non-nuclear missile use is provided. In certain situations, an enhanced theater missile defense could help the US and their partners to strengthen regional deterrence, but not in all situations. The analysis of both sides’ doctrinal provisions help to understand how strengthening the regional missile defense by the US and their partners can destabilize the situation. It is concluded that theater missile defense, unlike arms control measures, is not a reliable tool for ensuring regional stability.