Explain why the United States moved to a policy of isolationism following World War I.

The United States moved to a policy of isolationism because we wanted to stay out of the affairs of the world. After going through WWI, the nation wanted to keep to themselves.

Somewhat conversely American foreign policy has always tended towards isolationism. Ever since Washington's "avoid foriengn entanglements' speech the US has tried to avoid going outside it's own boarders except when it was patently in its best interests. After the Spanish-American War in 1898 and Teddy Roosevelt's Great White Fleet opened trade doors for US merchants into the Far East and Latin America the US retrenched in the idea of America first. Watching how the rest of the world was drawn into WWI it seemed to be a good idea. It was only when it was clear which side was going to win did the US agree to enter the war with an eye to have influence in the eventual peace.