Passage: While Sihanouk was out of the country on a trip to France, anti-Vietnamese rioting (which was semi-sponsored by the government) took place in Phnom Penh, during which the North Vietnamese and Viet Cong embassies were sacked. In the prince's absence, Lon Nol did nothing to halt these activities. On 12 March, the prime minister closed the port of Sihanoukville to the North Vietnamese and issued an impossible ultimatum to them. All PAVN/Viet Cong forces were to withdraw from Cambodian soil within 72 hours (on 15 March) or face military action.Sihanouk, hearing of the turmoil, headed for Moscow and Beijing in order to demand that the patrons of PAVN and the Viet Cong exert more control over their clients. On 18 March 1970, Lon Nol requested that the National Assembly vote on the future of the prince's leadership of the nation. Sihanouk was ousted from power by a vote of 86–3. Heng Cheng became president of the National Assembly, while Prime Minister Lon Nol was granted emergency powers. Sirik Matak retained his post as deputy prime minister. The new government emphasized that the transfer of power had been totally legal and constitutional and it received the recognition of most foreign governments. There have been, and continue to be, accusations that the U.S. government played some role in the overthrow of Sihanouk, but conclusive evidence has never been found to support them.The majority of middle-class and educated Khmers had grown weary of the prince and welcomed the change of government. They were joined by the military, for whom the prospect of the return of American military and financial aid was a cause for celebration. Within days of his deposition, Sihanouk, now in Beijing, broadcast an appeal to the people to resist the usurpers. Demonstrations and riots occurred (mainly in areas contiguous to PAVN/Viet Cong controlled areas), but no nationwide groundswell threatened the government. In one incident at Kampong Cham on 29 March, however, an enraged crowd killed Lon Nol's brother, Lon Nil, tore out his...

Question: The US government helped to overthrow who?
Sihanouk