Why go
Understanding the years from Sihanouk's rule to Phnom Penh's fall in 1975 makes Cambodia's memorial sites easier to place in time. The war was not one uninterrupted conflict: neutrality, cross-border fighting, bombing, a 1970 coup and the collapse of the Khmer Republic changed the country in stages.
The full story
Cambodia became independent from France in 1953 under Norodom Sihanouk. He later stepped aside as king to take part in politics, then returned as head of state after his father's death. His government declared neutrality as the Vietnam War intensified, but forces fighting in Vietnam used Cambodian territory, drawing the country into a widening conflict. US bombing and cross-border operations brought the war directly onto Cambodian soil. A coup in 1970 removed Sihanouk while he was abroad. Lon Nol's government established the Khmer Republic and demanded that Vietnamese communist forces leave. Civil war escalated. Sihanouk's support for the opposition helped the Khmer Rouge gain recruits, even though the movement had its own aims. Fighting involved Cambodian government forces, North Vietnamese troops and the growing Khmer Rouge insurgency; it cannot be reduced to a single two-sided struggle. By early 1975, Khmer Rouge forces had tightened their hold around Phnom Penh and cut vital supply routes. The Khmer Republic surrendered on 17 April 1975. That date marks the start of Khmer Rouge rule, covered separately in the next historical period. At sites concerned with the 1970s, keep the civil war and the regime that followed distinct: their causes, victims and institutions were related but not identical.