The Cambodian Civil War was a military conflict of the Cold War in Asia that pitted the guerrilla forces of the Maoist-oriented Communist Party of Kampuchea (nicknamed the Khmer Rouge) and the armed and security forces of the Nonaligned Kingdom of Cambodia from 1967 to 1970, then between the joint Monarchist, Maoist and Marxist-Leninist National United Front of Kampuchea alliance and the pro-western Khmer Republic from 1970 to 1975. Main combatants comprised:

The Khmer National Armed Forces (French: Forces Armées Nationales Khmères), best known by its French acronym FANK, were the official armed defense forces of the Khmer Republic from 1970 to 1975. Subordinated to the Ministry of Defense of the Cambodian Republican Government at the national capital Phnom Penh, the FANK branches were organized as follows: Khmer National Army (French: Armée Nationale Khmère – ANK) Khmer Air Force (French: Armèe de l'Air Khmère – AAK) Khmer National Navy (French: Marine Nationale Khmère – MNK) Paramilitary security forces: Khmer National Police (French: Police Nationale Khmère – PNK) Khmer National Gendarmerie (French: Gendarmerie Nationale Khmère – GNK) The Cambodian People's National Liberation Armed Forces (CPNLAF) were the official armed wing of the National United Front of Kampuchea (French: Front uni national du Kampuchéa or Front uni national khmer – FUNK), an umbrella organization dedicated to the armed overthrow of the pro-western Khmer Republic. Technically subordinated to the exiled Royal Government of the National Union of Kampuchea (French: Gouvernement royal d'union nationale du Kampuchéa – GRUNK) based in Beijing, the CPNLAF comprised the following three guerrilla movements: The Khmer Rumdo, also spelt Khmer Rumdos or Khmer Rumdoh ("Liberation Khmer" in the Khmer language), a pro-Sihanoukist (monarchist) faction founded in 1970, which was aligned with the People's Republic of China and North Vietnam. The Khmer Issarak ("Free Khmer" or "Independent Khmer" in the Khmer language), also known as the Khmer Viet Minh or United Issarak Front, a pro-Soviet Marxist-Leninist faction closely aligned with both the monarchist Khmer Romdo and North Vietnam. The Khmer Rouge, a collective designation coined to the Maoist-oriented Communist Party of Kampuchea (CPK) and its military wing, the Revolutionary Army of Kampuchea (RAK), active in Cambodia since 1967, which were aligned with the People's Republic of China, North Vietnam, the Viet Cong, the Pathet Lao and the Communist Party of Thailand. The Khmer Serei ("Free Khmer" in the Khmer language), a far-right, anti-communist and anti-monarchist guerrilla group active in Cambodia between 1955 and 1969, which was secretly backed by the United States and South Vietnam, being subsequently integrated into the FANK in 1970.Corfield and Summers, Historical Dictionary of Cambodia (2003), p. 225. The Army of the Republic of Vietnam (ARVN), which received support from the United States, Australia, Canada, France, West Germany, Israel, Japan, New Zealand, Philippines, South Korea, Pahlavi Iran, Francoist Spain, Taiwan, Thailand and the United Kingdom. The People's Army of Vietnam (PAVN), also designated the "North Vietnamese Army" (NVA), which received support from the Soviet Union, the People's Republic of China, North Korea, East Germany, Czechoslovakia, Poland, Hungary, Bulgaria and Yugoslavia.

A wide variety of weapons was used by all sides in the Cambodian Civil War. American military aid was funnelled to the FANK through the Military Equipment Delivery Team, Cambodia (MEDTC) program. Authorized a total of 113 officers and men, the team arrived in Phnom Penh in 1971,Nalty, Air War Over South Vietnam: 1968–1975 (2000), p. 276. under the overall command of CINCPAC Admiral John S. McCain Jr.Shawcross, Sideshow: Kissinger, Nixon and the destruction of Cambodia (1979), p. 190. In the early months of the War, most Cambodian Army infantry, armoured and artillery units fought the PAVN and Khmer Rouge with a mix of surplus World War II-vintage French and U.S. and modern Soviet and Chinese small-arms, armoured vehicles and artillery pieces either inherited from Khmer Royal Army stocks or delivered as emergency aid by the Americans.Bowra, Cambodia: analysis of U.S. military assistance to Cambodia, 1970–1975 (1983), p. 11.Conboy and Bowra, The War in Cambodia 1970–75 (1989), p. 11. ANK infantry battalions later sent to South Vietnam for retraining between February 1971 and November 1972 under the US Army-Vietnam Individual Training Program (UITG) were re-equipped upon their return to Cambodia with modern U.S. small-arms, comprising revolvers, automatic pistols, assault rifles, light machine guns, medium and heavy machine guns, grenade launchers, anti-tank rocket launchers, mortars and recoilless rifles. Besides infantry weapons, the U.S. MEDTC also provided the FANK branches with more modern U.S. military equipments, which included aircraft, armoured and transport vehicles and long-range artillery pieces, plus naval and riverine vessels.Sutsakhan, The Khmer Republic at War and the Final Collapse (1980), p. 182, Appendix C (Army Item).Sutsakhan, The Khmer Republic at War and the Final Collapse (1980), p. 183, Appendix C (Air Force Item).Sutsakhan, The Khmer Republic at War and the Final Collapse (1980), p. 183, Appendix C (Navy Item). Although the UITG and MEDTC aid programs allowed the FANK to standardise on modern U.S. weapons and equipment, they never superseded entirely the earlier weaponry, particularly in the case of the territorial units and rear-echelon support formations. In addition to U.S. support, the FANK received further military assistance from South Vietnam, the Kingdom of Laos,Conboy, FANK: A History of the Cambodian Armed Forces, 1970–1975 (2011), pp. 275–278. Thailand, Indonesia,Conboy and Bowra, The War in Cambodia 1970–75 (1989), p. 46. the Philippines,Conboy, FANK: A History of the Cambodian Armed Forces, 1970-1975 (2011), p. 258. Singapore,Conboy, FANK: A History of the Cambodian Armed Forces, 1970–1975 (2011), p. 246. the Republic of China (Taiwan), Australia and New Zealand.

During the early phase of the War, between 1967 and 1970, the Khmer Rouge likewise was largely equipped with WWII-vintage French, Japanese, American, and more modern Soviet and Chinese weapons either collected from arms caches established during the First Indochina War or seized from Khmer Royal Army units.Conboy and Bowra, The War in Cambodia 1970–75 (1989), p. 3. With the establishment of the FUNK coalition and the subsequent creation of its CPNLAF armed wing, the Khmer Rouge, the Khmer Rumdo and the Khmer Issarak began to receive military assistance mainly from North Vietnam, the Soviet Union, Albania, Romania, North Korea and the People's Republic of China.Conboy and Bowra, The War in Cambodia 1970–75 (1989), p. 33. As the war progressed, these factions were provided with modern Eastern Bloc military hardware, including semiautomatic and fully automatic small-arms, artillery pieces, armoured and transport vehicles of Soviet and Chinese origin, mostly being funnelled through the North Vietnamese. Although the CPNLAF standardized on Soviet and Chinese weapons and equipment by the time of their first full-scale solo offensive in January 1973,Conboy and Bowra, The War in Cambodia 1970–75 (1989), p. 34. its guerrilla forces continued to make use of captured enemy stocks until the end of the War.

Khmer National Armed Forces equipment Revolvers M1917 revolver Smith & Wesson Model 10

Pistols

Modèle 1935A pistol (7.65mm Longue): Received from France during the First Indochina War."Ground Order of Battle, Cambodia" Headquarters US Army, Pacific, May 1972. MAS-35-S pistol (7.65mm Longue): Received from France during the First Indochina War. FN P35 Colt.45 M1911A1Bowra, Cambodia: analysis of U.S. military assistance to Cambodia, 1970–1975 (1983), pp. 50–51. Smith & Wesson Model 39 Type 54 pistol: Chinese copy of the Soviet Tokarev TT-33.

Submachine guns

Sten: Received from France during the First Indochina War. MAT-49: Received from France during the First Indochina War. M1A1 Thompson M3/M3A1 Grease Gun

Bolt-action rifles

MAS-36: Received from France during the First Indochina War. MAS-36 CR39 folding-stock paratrooper rifle: Received from France during the First Indochina War. M1903 Springfield: Received from France during the First Indochina War and the United States.Thompson, The M1903 Springfield Rifle (2013), p. 63. Lee–Enfield SMLE Mk III: Received from France during the First Indochina War. Used in small numbers.Grandolini, Armor of the Vietnam War (2): Asian Forces (1998) p. 15.

Shotguns Ithaca 37 Pump-action

Carbines

MAS-49/56 Carbine: Received from France after the First Indochina War. M1 Carbine: M1 & M2 models were FANK standard issue concurrent with the M1 Garand rifle before receiving the M16.Bowra, Cambodia: analysis of U.S. military assistance to Cambodia, 1970–1975 (1983), p. 11.Conboy and Bowra, The War in Cambodia 1970–75 (1989), pp. 5; 33.Thompson, The M1 Carbine (2011), p. 67. M1A1 paratrooper carbine M2 Carbine: Full automatic variant. CAR-15 Assault carbine: Used by FANK special forces.

Sniper rifles M21 Sniper Weapon System

Semi-automatic rifles

MAS-49 rifle: Received from France during the First Indochina War. M1 GarandBowra, Cambodia: analysis of U.S. military assistance to Cambodia, 1970–1975 (1983), p. 11.Conboy and Bowra, The War in Cambodia 1970–75 (1989), p. 18. SKS: Used extensively in swamp and jungle environments. Type 56 semi-automatic rifle: Captured.

Assault rifles

M16A1 Assault rifleBowra, Cambodia: analysis of U.S. military assistance to Cambodia, 1970–1975 (1983), pp. 50–51.Conboy and Bowra, The War in Cambodia 1970–75 (1989), pp. 18; 42. FN FAL: Limited quantities received from Belgium. Used in small numbers. Heckler & Koch G3: Limited quantities received from West Germany. Used in small numbers. vz. 58 Assault rifle: Used in small numbers. AK-47 and AKS assault rifles: Used extensively in swamp and jungle environments.Conboy and Bowra, The War in Cambodia 1970–75 (1989), pp. 18; 38; 42.Rottman, The AK-47 Kalashnikov-series assault rifles (2011), p. 78. AKM and AKMS assault rifles: Used extensively in swamp and jungle environments. Type 56 and Type 56-1 assault rifles: Captured.

Light machine guns

FM 24/29: Received from France during the First Indochina War. Bren: Received from France during the First Indochina War. Used in small numbers. Degtyaryov DP/DPM M1918A2 BARConboy and Bowra, The War in Cambodia 1970–75 (1989), p. 42.

General-purpose machine guns M60: FANK standard-issue machine gun. M60B/M60D machine gun: mounted on UH-1D/H utility helicopters and UH-1G gunships.Conboy and Bowra, The War in Cambodia 1970–75 (1989), p. 43. RPD: Captured. Type 56 machine gun: Chinese copy of the RPD.Conboy and Bowra, The War in Cambodia 1970–75 (1989), p. 41. M1919A6 Browning light machine gunBowra, Cambodia: analysis of U.S. military assistance to Cambodia, 1970–1975 (1983), pp. 50–51.

Medium and Heavy machine guns

M1917 Browning machine gun: Limited service; used in small numbers. Browning M1919A4 .30 Cal Browning M2HB .50 Cal: Fitted to M113 APCs. SG-43/SGM Goryunov: Captured; mounted on wheeled APCs.Conboy, FANK: A History of the Cambodian Armed Forces, 1970–1975 (2011), pp. 193–195. DShKM: Captured; mounted on wheeled APCs.

Grenade systems

Alsetex OF37 grenade: Received from France during the First Indochina War.Rottman, The hand grenade (2015), pp. 16–18. Alsetex DF37 grenade: Received from France during the First Indochina War. F-1 hand grenade: Received from France during the First Indochina War. Mark 2 "Pineapple" fragmentation hand/rifle grenade M26 fragmentation hand grenade M59 "Baseball" hand grenade M61 fragmentation hand grenade M67 fragmentation hand grenade: FANK standard-issue fragmentation grenade. M18 colored smoke hand grenade M34 white phosphorus/smoke grenade