The new American President Richard Nixon, changed the policy. The New Policy was Vietnamisation. The Americans would train the South Vietnamese army to take care of the defence of South Vietnam. Nixon also began heavy bombing on North Vietnam once more but all attempts failed. At the end of 1972, the Vietcong exercised their control over the entire western half of the country. Nixon was under tremendous pressure, both at home and abroad, to withdraw from Vietnam. Finally, a cease-fire was arranged in January, 1973.
It was agreed that the American troops would be withdrawn from Vietnam and both North and South Vietnam would respect the frontier along the 17th parallel (line of 17° latitude between North and South Vietnam). But still the Vietcong continued the attack and Saigon, the majority of South Vietnam was occupied in 1975. Vietnam at last became united and free from foreign intervention. The United Vietnam came under a Communist Government. Thus, the American policy of preventing the spread of communism in South East Asia ended in failure.