HistoryData
Historical Conflict

Cambodian campaign

The 1970 Cambodian campaign extended the Vietnam War into neutral Cambodia to destroy PAVN/VC border sanctuaries, sparking major domestic protest in the United States.

Duration & Scope

1970 ongoing

< 1 year

Key Facts

Duration
April 29 – July 22, 1970 (ARVN); May 1 – June 30, 1970 (US)
Operations conducted
13 (ARVN) plus US operations
PAVN/VC troops targeted
~40,000
Objective
Destroy PAVN/VC bases and capture COSVN headquarters
Key trigger
Coup replacing Prince Sihanouk with pro-US General Lon Nol

Strategic Narrative Overview

Thirteen ARVN operations began April 29, 1970, with US forces joining May 1. Allied units captured several towns and seized large quantities of weapons, ammunition, and supplies from PAVN/VC base camps. However, the primary targets—roughly 40,000 enemy troops and the Central Office for South Vietnam (COSVN) command headquarters—largely evaded the cordon, as PAVN forces had withdrawn westward weeks before the offensive began, and a PAVN counter-offensive had already seized large parts of eastern Cambodia.

01 / The Origins

Cambodia's official neutrality had long allowed North Vietnamese and Viet Cong forces to use its eastern border regions as sanctuaries and supply routes. The United States, pursuing Vietnamization and a gradual withdrawal, sought to eliminate these cross-border threats. The March 1970 coup that deposed Prince Norodom Sihanouk and installed pro-American General Lon Nol created an opening for allied forces to enter Cambodian territory and strike PAVN/VC base areas directly.

03 / The Outcome

US forces withdrew from Cambodia by June 30, 1970, in compliance with a congressional deadline. ARVN operations continued until late July. Allied forces failed to destroy PAVN/VC troop strength or capture COSVN, but claimed success based on the volume of captured materiel. The campaign accelerated the Cambodian Civil War, deepened US domestic opposition to the Vietnam War, and contributed to the broader destabilization of Cambodia.

Belligerents & Mobilization Analysis

Side A

3 belligerents

United StatesRepublic of Vietnam (ARVN)Khmer Republic

Side B

2 belligerents

People's Army of Vietnam (PAVN)Viet Cong (VC)
Peak Mobilized Forces~40K
Forces vs Casualties ratio
0Mobilized
Outcome
Inconclusive; large materiel captured but PAVN/VC troops and COSVN HQ evaded destruction; US withdrew by June 30, 1970

Location

Map of CambodiaMap of CambodiaCambodia