The defeat of the French in 1954 and the First Indochina War led to the dissolution of French Indo China and the independence of Laos, Cambodia and Vietnam. But Vietnam was temporarily subdivided at the 17th parallel into a communist north and a non-communist south; elections were planned for 1956 to resolve the division. Thousands of Vietnamese migrated in a population exchange. Communists went north, and Roman Catholics moved south. Opposed to the Communist north, the United States began providing economic and military aid and supported South Vietnamese leader Ngo Dinh Diem's refusal to hold the elections, believing that the north, under Ho Chi Minh, would win. North Vietnam encouraged Communist organisation in the south, through the former Vietminh, who had fought the French and supplied them through the Ho Chi Minh Trail. The south became the battleground for a long and treacherous guerrilla war. In 1960, North Vietnam announced the formation of the Vietcong and the National Liberation Front. Concerned that there would be a domino effect, President Kennedy expanded military and economic aid. By 1962, 11,000 advisors and special forces were in Vietnam to support the ARVN (the Army of South Vietnam). But despite this support, the army was defeated by the Vietcong in a battle at Ap Bac in January 1963. Diem's persecution of Buddhist monks caused more problems.