Royal Seal of Approval: In 1965, Prince Norodom Sihanouk, Cambodia’s head of state, asserted the nation’s opposition to the U.S.-backed government in South Vietnam by allowing North Vietnamese guerrillas to set up bases within Cambodia’s borders. The North Vietnamese had an alliance with a Cambodian Marxist insurgency group, the Khmer Rouge, whose top brass Sihanouk is pictured here with in 1973. (Time Inc)