Military and Foreign Policy
America’s foreign policy has changed over time reflecting the change in its national interest. As a new nation after the Revolutionary War, America’s prime national interest was to maintain its independence from more powerful European countries. Protected by the Atlantic Ocean, its major foreign policy, as typified by the Monroe Doctrine, was to limit European attempts of further colonization of the Western Hemisphere. Through the 19th century, America concentrated on creating a nation that spanned the continent, and it avoided foreign entanglements. Once industrialized and more prosperous, it began looking for foreign markets and colonies. By the turn of the 20th century, the United States had become a minor imperial power, fighting a war with Spain for Cuba and the Philippines and annexing Hawaii and several other territories. World War I engaged the United States in European affairs, but after the war, a wave of isolationist feeling swept the country. Refusing membership in the League of Nations, America turned inward once again. Absorbed by the prosperity of the 1920s and the Great Depression of the 1930s, America let its military strength erode. It was not prepared for war when the Japanese struck the U.S. fleet at Pearl Harbor in late 1941.