Definition: "The political and economic doctrine that aims to replace private property and a profit-based economy with public ownership and communal control of at least the major means of production (e.g., mines, mills, and factories) and the natural resources of a society. Communism is thus a form of socialism—a higher and more advanced form, according to its advocates" (Britannica).
The term cold war itself, made popular in a 1946 speech by Prime Minister Winston Churchill of Britain, describes the ideological fight between democracy and Communism that began shortly after the end of World War II and lasted until 1991. For the foreign policy of the United States, the cold war defined the last half of the twentieth century. It was a war of ideas, of threats, and of actual fighting in the countries of Korea and Vietnam, pitting western nations against the Soviet Union and China and their Communist allies. The 1940s and 1950s saw the cold war bloom into a period of incomparable suspicion, hostility, and persecution. Anti-Communist hysteria ran through each branch of government as the pursuit of U.S. Communists and their sympathizers consumed the energies of the Executive Branch, lawmakers, and the courts. Rarely in the nation's history have constitutional rights been so widely and steadily sacrificed.