A polity in this present-
A polity in this present-day country used the baray irrigation system and declared independence from "Java" under Jayavarman II. That polity in this country fought against its eastern neighbor, Champa, and built the world's largest religious monument. It was bombed in Operations Menu and Freedom Deal in a continuation of nearby Operation Rolling Thunder. Its king Sihanouk was deposed by (*) Lon Nol. A communist regime that took over this country in 1975 conducted mass executions of intellectuals at the Killing Fields, including near the Angkor Wat. For 10 points, identify this state in Southeast Asia, ruled from 1975 to 1979 by dictator Pol Pot's Khmer Rouge.
A polity in this present-day country used the baray irrigation system and declared independence from "Java" under Jayavarman II.