This report considers potential implications for U.S.-China relations. China's actions for asserting and defending its maritime territorial and exclusive economic zone (EEZ) claims in the East China (ECS) and South China Sea (SCS), particularly since late 2013, have heightened concerns among observers that ongoing disputes over these waters and some of the islands within them could lead to a crisis or conflict between China and a neighboring country such as Japan, the Philippines, or Vietnam.

This report presents background information and discusses potential issues for Congress relating to U.S. ballistic missile defense (BMD) efforts in the Asia-Pacific region. These efforts pose several potential policy, funding, and oversight issues for Congress. Decisions that Congress makes on these issues could affect U.S. defense funding requirements and military capabilities, and U.S. relations with countries in the Asia Pacific region, including China, Japan, South Korea, North Korea, and Australia.