RETURN World War II 

The isolationist policy adopted in the 1930s was severely tested by the events in Europe during 1939 and 1940. Opinion in the US became increasingly polarized between those who favored supporting Britain and those who were opposed to another involvement in a European war. Gradually, however, opinion began to swing behind the former position and, in the fall of 1940, Congress imposed a draft, the first peacetime draft in the country’s history, to build up its military forces. A few months later the President secured Congressional approval to supply Britain with munitions. 

In December 1941 the issue was forced by the devastating Japanese attack on the chief American naval station in the Pacific, Pearl Harbor in Hawaii. The US was mobilized for total war, its enormous productive potential revitalized and public opinion massively engaged in the enterprise. While pursuing a holding action in the Pacific, attention was first directed to halting the German advances in Europe and the Soviet Union. As munitions and supplies streamed from American factories to Allied forces, US troops invaded North Africa and joined Allied forces in the push through the Mediterranean northward into continental Europe. Combined British and US air forces commenced day and night bombing of German cities and military installations in northern Europe. The joint Allied landing in France in the summer of 1944 and the subsequent advance on Germany by British, US and other allied forces from the west and the Soviet advance from the east led to the German surrender in 1945. 

In the Pacific, after a series of defeats, the American forces gained the ascendancy and began their advance on Japan. By the summer of 1945 they had the capability of bombing major Japanese cities with little opposition. In August of that year, Harry Truman, who had become president on the death of Roosevelt, authorized the military to drop the newly-developed atomic bomb on Hiroshima and a few days later on Nagasaki. Japanese resistance collapsed. The war was over, but the peace was elusive. 

At the Yalta Conference in February 1945 Roosevelt, Stalin and Churchill had laid out the territorial map of the world which would emerge from the war. The Soviet Union would control the countries of eastern Europe which it had occupied in the course of the war. Germany itself would be divided into zones occupied by Soviet and Allied forces. By default, Japan would be occupied by the US, except for certain territories Japan had seized earlier from Russian hands. 

Suspicion on the part of both the US and the Soviets with respect to one another’s objectives soon led to the so-called "cold war" in which both countries sought to restrain what they believed were the efforts of the other to expand into their respective spheres of influence. It appeared that the world would ultimately be taken over either by the forces of American capitalism or Soviet communism. To strengthen Europe against an expected Soviet invasion, the US sent massive financial assistance to help rebuild the devastated economies of western Europe. To help control the forces of nationalism elsewhere, generous support was given to the new United Nations organization. Despite its own tradition of protecting domestic industry against foreign competition, the US now came out in favor of multilateral agreements to support tariff reductions, supporting the General Agreement on Tariffs and Trade and the formation of regional trading blocs, apparently in the belief that such measures would encourage economic growth and development in the west and help build its ability to resist the forces of Soviet communism. These economic measures were supplemented, following the Berlin Blockade crisis of 1948-49, by the formation of the North Atlantic Treaty Organization which committed the US, the countries of Western Europe, Greece, Turkey and Canada to a mutual defense arrangement whereby any attack on one would be construed as an attack on all. 

While the position of the US and its western allies in Europe was being secured the situation in the Pacific deteriorated. The old British, French and Dutch colonies were collapsing and some appeared likely to be taken over by communists. In China the communists overwhelmed the nationalist army and in October 1949 made China a communist state. In Korea, the North Korean army invaded South Korea in June 1950 and the US used its position in the UN to organize a multinational, but predominantly US, military force to stop the North Korean advance. The expected victory of this force was denied, however, when massive Chinese support arrived to bolster the forces of the North. After a bloody contest the conflict ended in stalemate.