China and Japan are again openly squabbling over ownership of the uninhabited Senkaku Islands in the East China Sea. In the last week, Japanese officials took control of a lighthouse built on one of the eight small islands. The Senkakus are actually islets, which are 167 kilometers northeast of Taiwan and 426 kilometers southeast of Japan's Okinawa and have a total area of 6.3 square kilometers. Taiwan also claims the Senkakus, which were discovered by Chinese fishermen in the 16th century, and taken over by Japan in 1879. They are valuable now because of the 380 kilometer economic zone nations can claim in their coastal waters. This includes fishing and possible underwater oil and gas fields. A conservative Japanese political group built the lighthouse in 1986, to further claims of Japanese ownership. Currently, the Japanese have the most powerful naval forces in the region, and are backed up by a mutual defense treaty with the United States.