Location: Northeast of Taiwan in the East China Sea
Claimed by: Japan, China, Taiwan
The dispute: Diaoyu means "fishing platform" in Chinese, and there are records of these small rocks in Chinese navigation documents as far back as the 15th century. Japan's legal claim on the islands dates to 1895 (though some documents say it was earlier), when Taiwan and its surrounding islets were ceded to Japan at the end of the Sino-Japanese War. Tokyo formally incorporated them into Japanese territory shortly afterward.
After World War II, however, Japan ceded Taiwan and the Paracels (see below) back to China. And because Diaoyu was traditionally part of Taiwanese territory, the government in Taipei believes it has claim to the islands. Complicating matters further, because Beijing views Taiwan as part of Chinese territory, it also claims the islands. However, in 1970, the United States and Japan signed a treaty reverting occupied Okinawa back to Japanese control which, unlike the treaty signed after World War II, explicitly mentioned Senkaku as Japanese territory. Japan cites this bilateral agreement as legal backing for its claim.
The dispute would be little more than a historical curiosity if not for the sizable gas deposits believed to be located near the islands.
The territorial dispute has flared ever since with Japan expelling Chinese fishing boats from the region and Japanese nationalists traveling to the island to build a lighthouse in 1990. And in September, the dispute once again came to a head when a Chinese fishing boat captain was arrested after colliding with a Japanese warship, prompting the bitterest Sino-Japanese diplomatic standoff in decades.