During World War II the Japanese Empire invaded and the Second Philippine Republic, under Jose P. Laurel, was established as a puppet state. From 1942 the Japanese occupation of the Philippines was opposed by large-scale underground guerrilla activity. Atrocities and war crimes were committed during the war, including the Bataan Death March and the Manila massacre. Allied troops defeated the Japanese in 1945. By the end of the war it is estimated that over a million Filipinos had died. On October 11, 1945, the Philippines became one of the founding members of the United Nations. On July 4, 1946, the Philippines was officially recognized by the United States as an independent nation through the Treaty of Manila, during the presidency of Manuel Roxas.