Lon Nol
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".