 On March 18, 1970, Sihanouk, who was out of the country on a state visit, was deposed by a vote of the National Assembly and replaced by General Lon Nol.Cambodia's ports were immediately closed to North Vietnamese military supplies, and the government demanded that PAVN/NLF forces be removed from the border areas within 72 hours.On March 29, 1970, the Vietnamese had taken matters into their own hands and launched an offensive against the Cambodian army.