After the defeat of Spain during the Spanish–American War in 1898, the Philippines and other remaining Spanish colonies were ceded to the United States in the Treaty of Paris. The Philippines was under U.S. sovereignty until 1946, though occupied by Japan during World War II. In 1946, in the Treaty of Manila, the U.S. Recognized the Republic of the Philippines as an independent nation. Even after 1946, the U.S. maintained a heavy military presence in the Philippines, with as many as 21 U.S. military bases and 100,000 U.S. military personnel stationed there. The bases closed in 1992, leaving behind thousands of Amerasian children. Pearl S. Buck International foundation estimates there are 52,000 Amerasians scattered throughout the Philippines with 5,000 in the Clark area of Angeles. although an academic research paper presented in the U.S. (in 2012) by an Angeles, Pampanga, Philippines Amerasian college research study unit suggests that the number could be a lot more.