CONFUSION and frustration characterised the waning months of the United States presence in Lon Nol’s Cambodia, according to newly declassified documents published by the US state department on Friday.

The documents, which comprise hundreds of pages of conversations and memos from top US foreign policy officials, span January 1973 to July 1975, the period when the US was painstakingly extracting itself from the conflicts in Cambodia, Laos and Vietnam.

“What’s going on in Cambodia?” President Richard Nixon’s then-National Security Adviser Henry Kissinger asked during a meeting of top foreign policy and military officials on February 23, 1973.

Secretary of State James Schlesinger’s response, presented in the newly released documents, echoes the uncertain state of US policy towards Indochina in the dying days of the Vietnam War. “It’s as confused as ever,” he said.

The cables and transcripts chart how senior US officials tried to forge a settlement to end the civil war between the Lon Nol government and the Khmer Rouge, and their reactions to the end of congressional support for the war effort.

At several points, US officials debated how they might negotiate with the Khmer Rouge through Prince Norodom Sihanouk, the movement’s nominal head of state.

John Gunther Dean, then-Ambassador to Cambodia, wrote to the state department on February 18, 1975 outlining his advice for approaching Sihanouk: first, “be prepared to listen silently to a lengthy and violent diatribe about American wrongdoings in Indochina”; second, appeal to Sihanouk’s “ego”, and convince him that the US was genuinely interested in his leadership.

Dean argued that the US was the only country that could guarantee his security, and might even be able to “bring about the departure” of Khmer Rouge personalities Sihanouk did not approve of.

“What my argument boils down to is that we have only one card left to play in Cambodia [except for a bug-out] and that is Sihanouk,” Dean said.

Kissinger responded by outlining the numerous efforts that he and other American officials had undertaken to reach out to Sihanouk, in vain.

“The absence of a positive response, for which we presume Khmer Rouge opposition is a key factor, indicates they clearly prefer pursuing a military course,” he wrote on February 21. The documents also document the response of the Ford administration to the seizure of the SS Mayaguez and its American crew by Khmer Rouge forces off the country’s south coast on May 12, 1975.

US marines safely regained control of the ship on May 15, but 18 US troops were killed when three helicopters ferrying marines to a nearby island came under Khmer Rouge fire.