Video: 'President Richard Nixon Address to the Nation on the Situation in Southeast Asia, May 8, 1972'

(Monday, May 8, 1972, 9:00 p.m. EDT/Tuesday, May 9, 1972, 9:00 a.m. Saigon Standard Time; Operation Pocket Money, during the Easter Offensive, part of the Vietnam War, the Cold War and the Indochina Wars) — In a nationally televised address, U.S. President Richard Nixon announced tonight that the United States would lay mines in North Vietnam’s harbors in order to stop further supply of weapons and material.

The mines would be timed to become active after 72 hours.

Video: 'PBS Nixon (1990)_2of3' (May 8, 1972, at 51:26)

Nixon added, “To other nations, especially those which are allied with North Vietnam, the actions I have announced tonight are not directed against you. Their sole purpose is to protect the lives of 60,000 Americans, who would be gravely endangered in the event that the Communist offensive continues to roll forward, and to prevent the imposition of a Communist government by brutal aggression upon 17 million people.”

Video: 'Vietnam: A Television History (1983) – Ep 8/13: Vietnamizing the War (1968–1973)' (May 1, 1972, at 41:14)

In Operation Pocket Money, mines were dropped at Haiphong harbor by nine American attack aircraft flying from the carrier USS Coral Sea, and at six other ports, which were blocked for 300 days until the mines were removed by the U.S. in 1973.

Video: 'Vietnam: A Television History - Peace is at Hand [9/11]' (May 8, 1972, at 26:49)

Nixon also stepped up the bombing of North and South Vietnam, known as Operation Linebacker.