America’s involvement in the Spanish American War shattered the global equilibrium which had allowed the United States to grow and prosper in virtual isolation since 1815. When the United States decided to support Cuba’s struggle for independence with Spain, it marked a major departure from the traditional American practice of liberal nationalism. The 1898 Treaty of Paris ending the war gave Cuba its independence and also ceded important Spanish possessions to the United States—notably Puerto Rico, the Philippines, and the small island of Guam. The United States was suddenly a colonial power with overseas dependencies.
This assumption of colonial responsibilities reflected not only the temporary enthusiasms of 1898 but also marked a profound change in the diplomatic posture of the United States. The foreign policies of the early 19th century had less relevance at the dawn of the 20th century because the nation had changed. The United States had almost all the attributes of a great power—it stood ahead or nearly ahead of almost all other countries in terms of population, geographic size and location on two oceans, economic resources, and military potential. Foreign policy had to change to meet these new circumstances.
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. the 1890's, many Americans cast covetous eyes on outside US, on Samoa, Central America, and the Philippines. The US was building of first-rate navy by 1900. In 1895, during the Venezuela Boundary Dispute, the US took a hard line. It intervened in the Cuban War for Independence (the Spanish-American War). There was a flood of expansionist literature.
Emerging from World War II as the most powerful economic power on Earth, the United States changed its foreign policy dramatically. The World in the mid-19th Century
There were few changes in nation’s basic foreign policies; the overarching principles of isolation and neutrality generally remained firmly entrenched. Xenophobic Americans...