page_title: History of Cambodia
section_title: Khmer Republic and the War (1970–75)
hierarchical_section_title: History of Cambodia / Khmer Republic and the War (1970–75)
caption_attribution_description: English: Lon Nol
context_page_description: The history of Cambodia, a country in mainland Southeast Asia, can be traced back to Indian civilization. Detailed records of a political structure on the territory of what is now Cambodia first appear in Chinese annals in reference to Funan, a polity that encompassed the southernmost part of the Indochinese peninsula during the 1st to 6th centuries. Centered at the lower Mekong, Funan is noted as the oldest regional Hindu culture, which suggests prolonged socio-economic interaction with maritime trading partners of the Indosphere in the west. By the 6th century a civilisation, called Chenla or Zhenla in Chinese annals, firmly replaced Funan, as it controlled larger, more undulating areas of Indochina and maintained more than a singular centre of power.
  The Khmer Empire was established by the early 9th century. Sources refer here to a mythical initiation and consecration ceremony to claim political legitimacy by founder Jayavarman II at Mount Kulen in 802 CE. A succession of powerful sovereigns, continuing the Hindu devaraja cult tradition, reigned over the classical era of Khmer civilization until the 11th century.
context_section_description: While visiting Beijing in 1970 Sihanouk was ousted by a military coup led by Prime Minister General Lon Nol and Prince Sisowath Sirik Matak in the early hours of 18 March 1970.
  However, as early as 12 March 1970, the CIA Station Chief told Washington that based on communications from Sirik Matak, Lon Nol's cousin, that "the (Cambodian) army was ready for a coup". Lon Nol assumed power after the military coup and immediately allied Cambodia with the United States. Son Ngoc Thanh, an opponent of Pol Pot, announced his support for the new government. On 9 October, the Cambodian monarchy was abolished, and the country was renamed the Khmer Republic. The new regime immediately demanded that the Vietnamese communists leave Cambodia.
  Hanoi rejected the new republic's request for the withdrawal of NVA troops. In response, the United States moved to provide material assistance to the new government's armed forces, which were engaged against both CPK insurgents and NVA forces. The North Vietnamese and Viet Cong forces, desperate to retain their sanctuaries and supply lines from North Vietnam, immediately launched armed attacks on the new government. The North Vietnamese quickly overran large parts of eastern Cambodia, reaching to within 15 miles (24 km) of Phnom Penh. The North Vietnamese turned the newly won territories over to the Khmer Rouge. The king urged his followers to help in overthrowing this government, hastening the onset of civil war.
  In April 1970, US President Richard Nixon announced to the American public that US and South Vietnamese ground forces had entered Cambodia in a campaign aimed at destroying NVA base areas in Cambodia (see Cambodian Incursion). The US had already been bombing Vietnamese positions in Cambodia for well over a year by that point. Although a considerable quantity of equipment was seized or destroyed by US and South Vietnamese forces, containment of North Vietnamese forces proved elusive.
  The Khmer Republic's leadership was plagued by disunity among its three principal figures: Lon Nol, Sihanouk's cousin Sirik Matak, and National Assembly leader In Tam. Lon Nol remained in power in part because none of the others were prepared to take his place. In 1972, a constitution was adopted, a parliament elected, and Lon Nol became president. But disunity, the problems of transforming a 30,000-man army into a national combat force of more than 200,000 men, and spreading corruption weakened the civilian administration and army.
  The Khmer Rouge insurgency inside Cambodia continued to grow, aided by supplies and military support from North Vietnam. Pol Pot and Ieng Sary asserted their dominance over the Vietnamese-trained communists, many of whom were purged. At the same time, the Khmer Rouge (CPK) forces became stronger and more independent of their Vietnamese patrons. By 1973, the CPK were fighting battles against government forces with little or no North Vietnamese troop support, and they controlled nearly 60% of Cambodia's territory and 25% of its population.
  The government made three unsuccessful attempts to enter into negotiations with the insurgents, but by 1974, the CPK was operating openly as divisions, and some of the NVA combat forces had moved into South Vietnam. Lon Nol's control was reduced to small enclaves around the cities and main transportation routes. More than two million refugees from the war lived in Phnom Penh and other cities.
  On New Year's Day 1975, Communist troops launched an offensive which, in 117 days of the hardest fighting of the war, caused the collapse of the Khmer Republic. Simultaneous attacks around the perimeter of Phnom Penh pinned down Republican forces, while other CPK units overran fire bases controlling the vital lower Mekong resupply route. A US-funded airlift of ammunition and rice ended when Congress refused additional aid for Cambodia. The Lon Nol government in Phnom Penh surrendered on 17 April 1975, just five days after the US mission evacuated Cambodia.
caption: Lon Nol
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