The Sino-Japanese island dispute centers on a chain of uninhabited islands in the East China Sea, claimed as Senkaku by Japan and Diaoyu by China, both of which assert historical ownership. Tensions have escalated due to nationalism, past grievances from Japan's invasion in the 1930s-40s, and recent provocative actions, including Japan's purchase of the islands. Despite negotiations, high tensions continue between the nations, with no resolution evident.