On 30 April 1970, US President Richard Nixon publicly announced American and South Vietnamese plans to invade National Liberation Front (NLF) and People’s Liberation Armed Forces of Vietnam (PLAF) sanctuaries along Cambodia’s southeastern border with Vietnam, areas long established as resistance headquarters.
In his televised address, President Nixon outlined the reasons behind the planned incursion, often referring to the NLF’s persistent aggression and the need of retaliatory force.
Excerpt from President Nixon’s televised address (15:14)
The incursion, that would last from the end of April until the beginning of July, was set to embark on a series of operations to systematically target what were regarded as established sites used as headquarters by the NLF and the PLAF.
The first, named Operation Total Victory (Toàn Thắng 42), saw 12 Army of the Republic of Vietnam (ARVN) battalions, approximately 8,700 troops, cross the border into Cambodia from the south, an area designated the “Parrot’s Beak”. This stage of the incursion swept through Svay Rieng Province and into Kampong Trebek District, finally pathing a way to the capital Phnom Penh with Operations Kowloon (Cửu Long) I, II and III beginning on 10 April. Forces part of this operation would withdraw from Cambodia on 1 July.
Then, on the 1 April, 36 B-52s dropped 774 tons of bombs along the northern
“Fishhook” zone followed by a ground forces incursion of both US and ARVN troops, named Operation Rock Crusher (Toàn Thắng 43), that targeted Memot and Snoul. Memot had long been regarded as the position for the Central Office of South Vietnam (COSVN), formed in May 1961, and was considered the top prize for US and ARVN military personnel. US forces part of this operation would withdraw from Cambodia on 30 June; ARVN forces withdrew on 1 July.
The third operation, Operation Bold Lancer, began on the 6 April as a joint effort by US and ARVN troops, until their equal withdrawal on 30 June. This part of the incursion targeted Bases 353, 354 and 707, areas known to be occupied by the NLF.
Even though considered a successful incursion by the Nixon administration, the operation as a whole theoretically failed to achieve its objectives and further spoiled America’s military presence in Vietnam. Although ARVN and US troops captured large amounts of NLF and PLAF supplies and material, the allied forces failed to capture the Provisional Revolutionary Government of the Republic of South Vietnam (PRG) or NLF leadership. In essence, this primary military failure stemmed from the lack of understanding US and ARVN forces had of the NLF command structure. Rather than operating from a centralised base, much like the Pentagon or other Western military commands, the bases for resistance headquarters in South Vietnam were loose-knit entities, made up of small decentralised cells that were often far apart and ready to relocate at any time. This resulted in many of the PLAF and NLF leadership personnel fleeing the areas before American and ARVN troops arrived.
As well as the military failure of the operation, the US government suffered politically both at home and abroad. The bombings approved by President Nixon, as well as the troop incursion itself, was seen as an unlawful act by both the US Congress and the American public. Congressmen quickly moved to block the incursion by proposing an amendment to the Foreign Military Sales Act that would have cut off funding not only for US ground operations and advisors in Cambodia but would also have ended US air support for Cambodian forces. Seen as an escalation of the war into yet another country, anti-war protests erupted around the country, resulting in the shooting of four students at Kent University the following month.
Abroad, the failed incursion led to a semi-political victory for the Khmer Rouge, clearing the way for their dominance in government and their eventual rise as Cambodia’s dictatorial regime.