Neo-conservatism, which sprang in 1960s-1970s, has affected deeply not only the internal politics of U.S.A but also its foreign policies. The growth of Neo-conservatism was closely related to the unchecked spread of liberalism in the 1960s and the political circumstances both at home and abroad. The theoretical source of Neo-conservatism may come down to the wonderful combination of liberalism and conservatism of U.S.A. Neo-conservatism is characteristic of being conservative in internal policies and being open in foreign policies.