A Philippine gunboat harassed 12 Chinese fishing boats that were taking refuge from harsh weather in a lagoon near China's Huangyan Island last month, triggering the current standoff between China and the Philippines.

The Philippines never disputed China's sovereignty over the island until 1997, and a 1978 map sanctioned by the Philippines' National Mapping and Resource Information Authority placed Huangyan Island outside the Philippines' territorial limits. However, in May 1997, the Philippine navy intercepted two vessels carrying a group of amateur radio enthusiasts from China, Japan and the United States, who had planned an expedition to Huangyan Island. Before long, a group of Philippine congressmen sailed to the island and posed for photos under a Philippine flag, and later the Philippines navy arrested 21 Chinese fishermen near the island and filed an illegal entry charge against them.

Manila bases its claim on proximity and insists that the island is within its exclusive economic zone. The United Nations Convention on the Law of the Sea allows a coastal state to claim a 200-nautical-mile exclusive economic zone, but the state has no right to change the ownership of territory by doing so.