military defeat for them, it became a political victory, as it caused U.S. domestic support for the war to fade. By the end of the year, the VC held little territory and were sidelined by the PAVN. In 1969, North Vietnam declared the Provisional Revolutionary Government of the Republic of South Vietnam (PRG). Operations crossed national borders, and the U.S. bombed North Vietnamese supply routes in Laos and Cambodia. The 1970 deposing of the Cambodian monarch, Norodom Sihanouk, resulted in a PAVN invasion of the country (at the request of the Khmer Rouge), and then a U.S.-ARVN counter-invasion, escalating the Cambodian Civil War. After the election of Richard Nixon in 1969, a policy of "Vietnamization" began, which saw the conflict fought by an expanded ARVN, while U.S. forces withdrew in the face of increasing domestic opposition. U.S. ground forces had largely withdrawn by early 1972, and their operations were limited to air support, artillery support, advisors, and materiel shipments. The Paris Peace Accords of January 1973 saw all U.S. forces withdrawn; accords were broken almost immediately, and fighting continued for two more years. Phnom Penh fell to the Khmer Rouge on 17 April 1975, while the 1975 spring offensive saw the Fall of Saigon to the PAVN on 30 April, marking the end of the war; North and South Vietnam (under the PRG's control) were reunified under a communist state the following year. The war exacted an enormous human cost: estimates of the number of Vietnamese soldiers and civilians killed range from 966,000 to 3 million. Some 275,000–310,000 Cambodians, 20,000–62,000 Laotians, and 58,220 U.S. service members also died in the conflict. The end of the Vietnam War would precipitate the Vietnamese boat people and the larger Indochina refugee crisis, which saw millions of refugees leave Indochina, an estimated 250,000 of whom perished at sea. Once in power, the Khmer Rouge carried out the Cambodian genocide, while conflict between them and the unified Vietnam would eventually escalate into the Cambodian–Vietnamese War, which toppled the Khmer Rouge government in 1979. In response, China invaded Vietnam, with subsequent border conflicts lasting until 1991. Within the United States, the war gave rise to what was referred to as Vietnam Syndrome, a public aversion to American overseas military involvements, which, together with the Watergate scandal contributed to the crisis of confidence that affected America throughout the 1970s. Names Various names have been applied to the