Led by a cadre of French officers and senior NCOs, and intended to be used on internal security operations to reinforce CEFEO regular troops, the new Khmer battalions saw their first combat in 1947 against Vietminh guerrilla forces in north-eastern Cambodia.
Under an additional protocol signed in June 1950, Cambodian provincial governors were assigned the responsibility for the pacification of the provinces under their jurisdictions; to accomplish this mission they were given each a counter-insurgency force consisting of one independent Khmer infantry company.
[3] The ARK General Staff was filled entirely by French senior and intermediate rank officers, who did most of the command-and-control support, intelligence work and training, and supervised weaponry and equipment deliveries to the Khmer military units.
By mid-1953, however, at the instigation of their youthful King Norodom Sihanouk, Khmer military personnel began not only to participate in anti-French nationalistic demonstrations calling for complete Cambodian independence, but they also deserted French-led units by the hundreds.
In October that year, the French High Command finally agreed to transfer responsibility for Cambodian national security to the ARK and for that effect, another French-Khmer military agreement was signed.
Under the terms of this agreement, the French-led Khmer military units were to be transferred to the control of the Cambodian national authorities, and that an operational zone was to be created in the east bank of the Mekong and assigned to the French Union forces.
[9] The ARK continued to rely on French military assistance but at the same time turned to the Soviet Union, the People's Republic of China, Czechoslovakia, Britain, Belgium and West Germany for weapons, equipment and training.
[11] Most ARK units were concentrated in the northeast at Ratanakiri Province and on the Phnom Penh area; the latter was the headquarters of the six main Half-Brigades and supporting services whereas infantry formations were deployed throughout the country.
[12] With the exception of a few specialized units, most of these formations actually fell below strength, were poorly trained and equipped in a haphazard way with an array of French, American, British, Belgian, West German, Czechoslovakian, Chinese and Soviet weapon systems.
The motor pool consisted in a mixed inventory totalling 150 vehicles, including WWII-vintage U.S. Willys MB ¼-ton (4x4) jeeps, Land Rover (4x4) Series II, Soviet GAZ-69A (4x4) field cars and GAZ-63 (4x4) 2-ton trucks.
[48] Following the March 1970 coup, the new Head of State Marshal Lon Nol issued a general mobilization order and, after securing American, Thai and South Vietnamese military support, promptly set up ambitious plans to expand the Cambodian armed forces.
By June 1970, the rechristened Khmer National Army (French: Armée Nationale Khmère – ANK), had rapidly expanded to 110,000 men and women, though most of them were untrained raw recruits organized into a confusing array of French- and American-modelled combat formations,[49] staffed by elderly NCOs and inexperienced young officers.
[67] Although the UITG and MEDTC aid programs allowed the ANK to standardise on modern U.S. weapons, they never superseded entirely the earlier weaponry, particularly in the case of the territorial units and rear-echelon support formations.
The FANK suffered its first major setback in February 1971 during Operation Chenla I, an offensive launched earlier in late August 1970 targeting North Vietnamese strongholds in northeastern Cambodia, when a Cambodian Army combined twelve battalion-strong task-force was annihilated by a PAVN counterattack that ripped apart many elite Cambodian military units, including some of the American-trained Khmer Krom volunteer battalions recruited straight out of South Vietnam.
From then on, the Republican government focused on consolidating its hold over the key urban centers, the main garrisons and the lower Mekong-Bassac river corridors, thus leaving most of the countryside virtually open to Khmer Rouge recruiting drives.
[84] During the Battle of Kampong Cham in September 1973, the FANK High Command launched Operation "Castor 21", a successful combined amphibious assault by a joint task-force of Marines, SEALs and the Cambodian Army's 80th Infantry Brigade with the assistance of the Khmer National Navy (MNK) into the enemy-held half of the city.
The MNK ran some twenty convoys between Phnom Penh and Kampong Cham, despite sustaining heavy losses as the boats and landing crafts on the river transporting the FANK task-force units were exposed for six hours to enemy fire from the riverbanks.
Although at the Battle of Oudong the FANK task-force lost four landing crafts, and some 25 soldiers were killed at debarkation, the MNK did manage to deliver thirty M113 APCs, six trucks, four M101A1 105 mm towed field howitzers, and no less than 2,740 Marine and Army troops, who succeeded in recapturing the burn-out town.
[86][87] In January 1975, coinciding with the North Vietnamese spring offensive that shattered the South's defences apart, the Khmer Rouge closed in on Phnom Penh, already overcrowded with 250,000 civilian refugees, and besieged it.
President Lon Nol, FANK Commander-in-Chief Gen. Sosthene Fernandez and other Khmer Republic officials could not coordinate an effective resistance and at the same time feed the refugees and residents of the Cambodian Capital.
On April 1, Marshal Lon Nol resigned from the Presidency and left the Country by plane to Thailand, although most of the senior civilian and military government officials decided to stay.
[89] Even though their government had surrendered, ANK soldiers continued to fiercely hold their ground for nearly a month after the fall of Phnom Penh against several unsuccessful attempts by Khmer Rouge forces to reduce this last holdout.
Throughout the country, thousands of demoralized Cambodian men and women who had the misfortune of being captured wearing the Army uniform – ranging from officers to NCOs, and even ordinary soldiers, regardless if they had committed any war crimes or not – were rounded up by Khmer Rouge guerrilla units and massacred.
Reflecting the increasing American influence, ANK senior officers adopted in 1970–71 a new dress uniform, which consisted of an Olive Green tunic and slacks worn with a white shirt and black tie.
[97] Female personnel were issued a service and working olive green OG-107-style short-sleeved blouse based on their male counterparts' versions, provided with two patch breast pockets closed by straight or pointed flaps and shoulder straps.
[100] Berets were worn pulled to the left in French fashion, with the colour sequence as follows: General Service – Light Khaki, Infantry – Light Olive Drab, Armoured Corps – Black, Paratroopers and Para-Commandos – Cherry-red (Maroon), Special Forces – Forest Green, Military Police and Regional Gendarmerie – Dark Blue; berets made of "Tigerstripe" and "Highland" camouflage cloth were also issued to elite units.
ARK officers received a light khaki service peaked cap based on the French M1927 pattern (French: Casquette d'officier Mle 1927) to wear with the khaki service dress, whilst a white summer top version was worn with the FARK white full dress uniform; both versions were worn with a gilded metal FARK cap badge bearing the royal coat-of-arms.
[101] In addition, a wide range of OG or camouflage Boonie hats and baseball caps also found their way into the ANK from the U.S., South Vietnam and Thailand though they never displaced entirely the earlier headgear.
[102] During the Republic, the ANK standardized on the M-1 model 1964 provided with the U.S. Army Mitchell "Clouds" camouflage pattern cover, though some units retained the older U.S. and French steel helmets throughout the war.
This basic system was maintained during the Republic, though standard black shoulder boards without the royal crest were adopted in 1970 for all services and from 1972 onwards some Cambodian officers began wearing metal pin-on collar rank insignia, obviously inspired by American practice.