for social approval and belonging to a community, even one as twisted as the KR, contributed to obedience, motivating violence within Cambodia. Economy Democratic Kampuchea's economic policy was similar to, and possibly inspired by, China's radical Great Leap Forward that carried out immediate collectivisation of the Chinese countryside in 1958. During the early 1970s, the Khmer Rouge established "mutual assistance groups" in the areas they occupied. After 1973, these were organised into "low-level cooperatives" in which land and agricultural implements were lent by peasants to the community but remained their private property. "High-level cooperatives", in which private property was abolished and the harvest became the collective property of the peasants, appeared in 1974. "Communities", introduced in early 1976, were a more advanced form of high-level cooperative in which communal dining was instituted. State-owned farms also were established. Far more than the Chinese communists, the Khmer Rouge pursued the ideal of economic self-sufficiency, specifically the version that Khieu Samphan had outlined in his 1959 doctoral dissertation. Currency was abolished, and domestic trade or commerce could be conducted only through barter. Rice, measured in tins, became the most important medium of exchange, although people also bartered gold, jewelry, and other personal possessions. Foreign trade was almost completely halted, though there was a limited revival in late 1976 and early 1977. China was the most important trading partner, but commerce amounting to a few million dollars was also conducted with France, the United Kingdom, and with the United States through a Hong Kong intermediary. From the Khmer Rouge perspective, the country was free of foreign economic domination for the first time in its 2,000-year history. By mobilising the people into work brigades organised in a military fashion, the Khmer Rouge hoped to unleash the masses' productive forces. There was an "Angkorian" component to economic policy. That ancient kingdom had grown rich and powerful because it controlled extensive irrigation systems that produced surpluses of rice. Agriculture in modern Cambodia depended, for the most part, on seasonal rains. By building a nationwide system of irrigation canals, dams, and reservoirs, the leadership believed it would be possible to produce rice on a year-round basis. It was the "new people" who suffered and sacrificed the most to complete these ambitious projects. Although the Khmer Rouge implemented an "agriculture first" policy in order to achieve self-sufficiency, they were not, as some observers have argued, "back-to-nature" primitivists. Although the