スカボロー礁
Historically, the Philippine boundary has been defined by its 3 treaties, Treaty of Paris (1898), Treaty of Washington (1900) and "Convention regarding the boundary between the Philippine Archipelago and the State of North Borneo". Many analysts consider that the 1900 Treaty of Washington concerned only the islands of Sibutu and Cagayan de Sulu., but a point of view argued that Scarborough Shoal has been transferred to the United States based on the Treaty of Washington (1900), ignoring the fact that the cession documents from the United States to the Philippines did not have any reference to the Scarborough Shoal.