An uninhabited island group with three names and three claimants
Under 3 square miles of rock, currently administered by Japan — and formally claimed by both China and Taiwan, each under its own name. This is a naming dispute layered on top of a live territorial one.
Senkaku Islands
Administered by Japan since 1972, as part of Ishigaki City, Okinawa Prefecture. Japan's position is that no sovereignty dispute exists to negotiate.
Diaoyu Islands
China cites historical records referencing the islands dating back centuries, and maintains its own patrols in nearby waters to assert the claim.
Diaoyutai Islands
Taiwan makes a historical claim similar to China's, administered on paper as part of Yilan County — a separate claim from, not coordinated with, Beijing's.
Nobody lives there, but the waters around it matter. The islands themselves are barren and uninhabited, but the surrounding waters hold fishing grounds and potential undersea gas reserves, and sit near busy shipping lanes. Japanese coast guard vessels routinely intercept Chinese and Taiwanese boats entering waters Japan considers its own — incidents that periodically escalate into diplomatic standoffs between the three governments.
Sources: Japan Ministry of Foreign Affairs; China Ministry of Foreign Affairs; Taiwan Ministry of Foreign Affairs — official position statements from all three governments. Country shapes: Natural Earth.