In a U.S.-supported uprising, Lon Nol ousted Prince Sihanouk (See April 27) from power in Cambodia. Soon thereafter, U.S. and South Vietnamese troops extended the war to Cambodia. Sihanouk joined forces with the leftist Khmer Rouge in guerrilla fighting.
When Pres. Nixon announced that U.S. combat troops would join South Vietnamese troops in invading Cambodia to destroy enemy supply bases and concentrations, he precipitated the Cambodian crisis.
The U.S. Senate voted to repeal the ill-fated Tonkin Gulf Resolution, which had given the two administrations carte blanche to conduct their policies in Vietnam.
The Senate passed the Cooper-Church Amendment, barring the use of U.S. troops in Cambodia. At the same time, Nixon announced the end of combat operations in Cambodia and promised that in the future the U.S. would provide only air support for South Vietnamese operations.
An eight-point statement of terms was submitted to the Paris conference by the NLF delegate. The statement seemed designed to commit the U.S. to withdrawal of all foreign troops from South Vietnam by June 30, 1971, and to the replacement of the existing South Vietnamese government by a coalition in which the NLF would share power.
Pres. Nixon outlined a major new initiative for peace: a general cease-fire throughout all Indochina, with international supervision; an international conference to settle Indochinese problems; negotiations of a timetable for complete withdrawal of forces from South Vietnam; a South Vietnamese settlement reflecting the will of the people and the existing relationships of political forces; and immediate and unconditional release of all prisoners of war.