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, and that the United States could be drawn into such a crisis or conflict as a result of obligations the United States has under bilateral security treaties with Japan and the Philippines.