Operation Birmingham was a military operation of the Vietnam War

Vietnam War

The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...

 in War Zone C

War zone C

A Vietnamese communist base area located in Tay Ninh province near the Cambodian border during the Vietnam war. Reportedly the general location of COSVN, the headquarters for communist military and political activities in the southern half of Vietnam....

, north of Saigon. The US 1st Infantry Division and the ARVN 5th Division conducted operations on the eastern flank of War Zone C. The goals were opening Route 13

National Road 13 (Vietnam)

National Route 13 is a highway in southern Vietnam stretching from the northeastern outskirts of Ho Chi Minh City, the commercial centre of the country, towards the border to Cambodia...

 from Saigon to the north and engaging the Viet Cong 9th Division. The Viet Cong suffered heavy losses, but managed to withdraw beyond the Cambodian

Cambodia

Cambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia...

border. In addition to the large number of Viet Cong casualties, approximately 500 tons of weapons; ordnance; rice, salt and other foods were seized by anti-communist forces.