Dap Chhuon affair

The Dap Chhuon affair, also known as the 1959 Cambodian coup attempt, was the anti-Sihanouk plot by Dap Chhuon, Sam Sary, and Son Ngoc Thanh as well as the supporting roles played by Thailand, South Vietnam, and the United States in the plot. More than any other incident in US–Cambodian relations, the failed Dap Chhuon coup convinced Sihanouk that the United States was implacably hostile to Cambodian neutrality and to him personally. The conspicuous absence of an American warning, however, raised the disturbing possibility that the United States was behind the conspiracy.^[3] Dap Chhuon’s coup collapsed without a shot being fired, and CIA operative Victor Matsui’s contact with the rebels was particularly damaging to US relations with Sihanouk.^[4]