Cambodian campaign

The objective of the Cambodian campaign was the defeat of the approximately 40,000 troops of the People's Army of Vietnam (PAVN) and the Viet Cong (VC) in the eastern border regions of Cambodia. Cambodian neutrality and military weakness made its territory a safe zone where PAVN/VC forces could establish bases for operations over the border. With the US shifting toward a policy of Vietnamization and withdrawal, it sought to shore up the South Vietnamese government by eliminating the cross-border threat.

A change in the Cambodian government allowed an opportunity to destroy the bases in 1970, when Prince Norodom Sihanouk was deposed and replaced by General Lon Nol. A series of South Vietnamese–Khmer Republic operations captured several towns, but the PAVN/VC military and political leadership narrowly escaped the cordon. The operation was partly a response to a PAVN offensive on 29 March against the Cambodian Army that captured large parts of eastern Cambodia in the wake of these operations. Allied military operations failed to eliminate many PAVN/VC troops or to capture their elusive headquarters, known as the Central Office for South Vietnam (COSVN) as they had left a month prior.