One of the most challenging security issues in the region is the conflicting claims between China and Japan, two major powers in the Asia-Pacific, over the ownership of Diaoyu Islands (in Chinese) or Senkaku Islands (In Japanese) in the East China Sea. The U.S. declared that it does not take an official position on who own the islands, it has made clear to the world that the islands are included within the Treaty of Mutual Cooperation and Security between the U.S. and Japan, which would require the U.S. to help Japan in defending the islands if China attempts to occupy them. Also, president Obama made it very clear that the Treaty covers all territories under Japan’s administration, including the Senkaku Islands.