On April 1, 1975, 16 days before the Khmer Rouge captured Phnom Penh, Lon Nol fled to the United States, first to Hawaii and then to California, where he remained until his death in 1985.

[3] His father Lon Hin was the son of a Khmer Krom from Tay Ninh Province[4] who later served as a district chief in Siem Reap and Kampong Thom, after making a name for himself 'pacifying' bandit groups in Prey Veng.

While Sihanouk, in an attempt to distance his country from the effects of the Vietnam War, was pursuing a foreign policy of "extreme neutrality", which involved association with China and toleration of North Vietnamese activity on the eastern borders, Nol remained friendly towards the United States, and indicated that he regretted the ending of US aid after 1963.

[9] Lon Nol became prime minister, and the following year troops carried out a savage repression of a leftist-inspired revolt, the Samlaut Uprising, in Battambang Province.

Sihanouk later claimed that the 1970 coup against him was the result of an alliance between his longstanding enemy, exiled politician Son Ngoc Thanh and Sirik Matak, with CIA support and planning.

[15] It seems likely that in setting in motion the events leading up to the coup, Lon Nol initially intended to strengthen his position against the North Vietnamese with the ultimate aim of preventing their troops (and those of the Viet Cong) from operating within Cambodian borders, and wished to apply pressure on Sihanouk to achieve this.

On the night of 17 March, Sirik Matak, accompanied by three army officers, went to the Prime Minister's residence and compelled a weeping Lon Nol to sign the necessary documents at gunpoint.

On 28 and 29 March there were large-scale popular demonstrations in favour of Sihanouk in several provincial cities, but Lon Nol's forces suppressed them, causing several hundred deaths.

His rule became increasingly erratic and authoritarian: he appointed himself Marshal (a title previously unknown in Cambodia) in April 1971, and in October suspended the National Assembly, stating he would no longer "vainly play the game of democracy and freedom" in wartime.

[21] Backed by his forceful, ambitious younger brother General Lon Non, Nol succeeded in reducing the influence of Sirik Matak, In Tam and the other coup leaders.

In time Lon Nol's regime became completely dependent upon large quantities of American aid that towards the end were not backed by the political and military resolve needed to effectively help the beleaguered republic.

Lon Nol was increasingly dependent on the advice of soothsayers and Buddhist mystics: at one point during a Khmer Rouge assault on Phnom Penh, he sprinkled a circular line of consecrated sand in order to defend the city.