U.S. and South Vietnamese forces enter Cambodia

Nixon announced a gradual transfer of combat responsibilities to South Vietnamese forces while U.S. troops were withdrawn. The policy reduced direct U.S. ground exposure but prolonged fighting and...

A major mobilization brought hundreds of thousands to Washington to demand an end to the war. The event followed the October Moratorium and demonstrated sustained public opposition as U.S. forces...

The National Assembly voted to remove Sihanouk while he was abroad, and Lon Nol took power. The change drew Cambodia deeper into regional conflict. Cambodian political actors and civilians had their...

Cambodia’s National Assembly removed Prince Norodom Sihanouk and Lon Nol assumed power. The change reshaped regional politics and preceded the U.S.-South Vietnamese incursion; Cambodian sovereignty...

A U.S. directive authorized the deployment of U.S. and South Vietnamese ground forces into Cambodia. The campaign widened the war into a formally neutral state and provoked intense opposition in the...

National Guard troops fired on students during protests against the Cambodia incursion, killing Allison Krause, Jeffrey Miller, Sandra Scheuer and William Schroeder. The shootings intensified the...

Tens of thousands gathered in Washington, D.C., after the Cambodian campaign and the deaths of students at Kent State. The protest connected opposition to the foreign war with domestic state...

Mississippi police and highway patrol officers fired into Alexander Hall during campus unrest, killing Phillip Gibbs and James Green and wounding others. The shootings followed Kent State but received...

Congress enacted restrictions on U.S. ground forces and advisers in Cambodia through the Cooper-Church amendment. The measure reflected legislative resistance to the expansion of the war and a renewed...

Operation Lam Sơn 719 sent South Vietnamese forces into Laos to disrupt supply routes, with U.S. air support but no U.S. ground combat units. The operation suffered major losses and demonstrated the...