Extension of the war into Cambodia and Laos (1970-1971)
- On 4th May 1970, in a protest at Kent State University, Ohio, four students were killed and nine injured by National Guard soldiers. The killings sparked off over 400 protests and strikes.
- A week after the shootings, 100,000 anti-war demonstrators converged on Washington, D.C. to protest at the shooting of the students in Ohio and the incursion of the Nixon administration into Cambodia.
- Although the demonstration was quickly put together, protesters were still able to bring out thousands to march in Washington. It was an almost spontaneous response to the events of the previous week.
- Soon afterwards, a National Student Strike occurred. More than 450 university, college and high school campuses across the country were shut by student strikes and both violent and non-violent protests.
- In military terms, the invasion of Cambodia achieved little and US troops withdrew after two months.
- In February 1971, Nixon approved a South Vietnamese invasion of Laos to block the Ho Chi Minh Trail. ARVN forces were supported by US planes.
- After six weeks, the South Vietnamese troops withdrew, losing nearly 50% killed or wounded. The failure of the ARVN proved that the South Vietnamese, on their own, could not stand up to the North Vietnamese.