The two main winners of World War II, who had been Allies during the war, became superpowers and competitors as soon as the war ended, each with their own spheres of influence and client states. After the 1953 coup, Iran became one of the client states of the United States. In his earlier book, "U.S. Foreign Policy and the Shah: Building a Client State in Iran", Gasiorowski identifies the client states of the United States and of the Soviet Union during 1954–1977. Gasiorowski identified Cambodia, Guatemala, Indonesia, Iran, Laos, Nicaragua, Panama, the Philippines, South Korea, South Vietnam, and Taiwan as strong client states of the United States and identified those that were moderately important to the U.S. as Bolivia, Brazil, Colombia, Costa Rica, Dominican Republic, Ecuador, El Salvador, Greece, Haiti, Honduras, Israel, Jordan, Liberia, Pakistan, Paraguay, Thailand, Tunisia, Turkey, and Zaire. He named Argentina, Chile, Ethiopia, Japan, and Peru as "weak" client states of the United States.