Sihanouk himself claimed that the coup was the result of an alliance between his longstanding enemy, the exiled right-wing nationalist Son Ngoc Thanh, the politician Prince Sisowath Sirik Matak (depicted by Sihanouk as a disgruntled rival claimant to the Cambodian throne) and the CIA, who wished to install a more US-friendly regime. There is in fact little if any evidence of CIA involvement in the coup, although it seems that sections of the US military establishment – notably the Army Special Forces – may have had some involvement in terms of offering support and training to the plotters after being approached by Lon Nol.