capita only started to increase after the 1980s. Sihanouk's peacetime economy (1953–1970) Sihanouk's political neutrality, which formed the cornerstone of his foreign policy, had a significant effect on Cambodia's economic development. Sihanouk insisted that the economic dimension of neutrality meant either total rejection of international aid (as practiced by Burma under Ne Win) or acceptance of foreign economic assistance from all countries without strings attached. Indeed, during the first decade that he was in power in newly independent Cambodia (1953–63), the prince carefully practiced his "purer form of neutrality between East and West" in seeking foreign economic assistance for development (see Cambodia under Sihanouk, 1954–70, ch. 1). In 1963 however, Cambodia's economy started to stagnate when Sihanouk decided to link his economic neutrality policy to the country's territorial integrity and border security. He rejected further assistance from the United States, because Washington supported the Republic of Vietnam (South Vietnam), and from Thailand, with which Cambodia had continuous frontier disputes. In a related move, Sihanouk nationalized trading companies, banks, insurance, and major industries, thereby causing economic deterioration between 1963 and 1969. The 1967 Samlot (Batdambang) revolt and the February 1970 government decision to demonetize (or exchange) the old 500 riel (for value of the riel—see Glossary) banknotes were crucial events contributing to the end of the Sihanouk era (see Into the Maelstrom: Insurrection and War, 1967–75, ch. 1; The Second Indochina War, 1954–75, ch. 5). During his tenure after independence, Sihanouk used the country's ill-defined constitution to monitor all government activities of any consequence and to bend the government's decision-making process to his advantage. During the course of nation building, political aims often prevailed over strictly economic objectives. For example, prior to 1967, the government assigned higher priority to social improvements, such as health and education, than it did to national economic growth. The government later gave higher priority to the productive sectors of agriculture and industry in economic plans for the 1968-72 periods; however, because of war, the government did not implement these plans. Nonetheless, between 1952 and 1969, Cambodia's gross national product (GNP—see Glossary) grew an average of 5 percent a year in real terms, with growth higher during the 1950s than during the 1960s. In addition, the service sector played an important role in Sihanouk's mixed economic system in contrast to its position under the regimes of Pol Pot and of Heng Samrin, who considered the service sector