Cambodian Coup of 1970 - Background

Background

For more details on this topic, see Cambodia under Sihanouk (1954–1970).

Since independence from France in 1954, Cambodia had been led by Prince Norodom Sihanouk, whose Sangkum political movement had retained power after winning the 1955 parliamentary election. In 1963, Sihanouk had forced the National Assembly to approve a constitutional amendment that made him head of state with no fixed term of office. He had retained domestic power through a combination of political manipulation, intimidation, patronage, and careful balancing of left- and right-wing elements within his government; whilst placating the right with nationalist rhetoric, he appropriated much of the language of socialism to marginalize the Cambodian communist movement, who he proprietorially referred to as the Khmers Rouges ("Red Khmers").

With the Second Indochina War escalating, Sihanouk's balancing act between left and right became harder to maintain. Cross-border smuggling of rice also began to have a serious effect on the Cambodian economy. In the Cambodian elections of 1966, the usual Sangkum policy of having one candidate in each electoral district was abandoned; there was a huge swing to the right, especially as left-wing deputies had to compete directly with members of the traditional elite, who were able to use their local influence. Although a few communists within the Sangkum – such as Hou Yuon and Khieu Samphan – chose to stand, most leftists were decisively defeated. Lon Nol, a rightist who had been a longstanding associate of Sihanouk, became Prime Minister.

By 1969, Lon Nol and the rightists were growing increasingly frustrated with Sihanouk. Although the basis for this was partly economic, political considerations were also involved. In particular, the nationalist and anti-communist sensibilities of Lon Nol and his associates meant that Sihanouk's policy of semi-toleration of Viet Cong and Vietnam People's Army activity within Cambodian borders was unacceptable; Sihanouk, during his swing to the left in 1963–66, had negotiated a secret arrangement with Hanoi whereby in return for the guaranteed purchase of rice at inflated prices, the port of Sihanoukville was opened for weapons shipments to the Viet Cong. As well as the rightist nationalists, the liberal modernising elements within the Sangkum, headed by In Tam, had also become increasingly alienated by Sihanouk's autocratic style.

There is evidence that during 1969 Lon Nol approached the US military establishment to gauge military support for any action against Sihanouk. Lon Nol's appointee as deputy Prime Minister, Prince Sisowath Sirik Matak – a US-friendly nationalist and leader of the Cambodian business community – is thought to have suggested that Sihanouk should be assassinated, though Lon Nol rejected this plan as "criminal insanity". Sihanouk himself thought that Sirik Matak (who he characterised as a jealous rival claimant to the Cambodian throne) backed by the CIA, and in contact with exiled Sihanouk opponent Son Ngoc Thanh, had suggested the coup plan to Lon Nol in 1969. CIA involvement in the coup plot remains unproven, and Henry Kissinger later claimed that events would take the US government by surprise, but it seems likely that at least some military intelligence agents were partly culpable. It is also known that the US military had drawn up plans for an invasion of Cambodia in 1966-7, and were upset that Lyndon B. Johnson would not approve them.

Declassified documents indicate that, as late as March 1970, the Nixon administration was hoping to garner "friendly relations" with Sihanouk.