What led the US from isolationism to involvement?

Answer 1

The U.S. transitioned from isolationism to involvement primarily due to the increasing threat posed by aggressive totalitarian regimes in Europe and Asia during the 1930s and early 1940s. The attack on Pearl Harbor in December 1941 galvanized American public opinion and government policy, propelling the nation into World War II. Additionally, economic interests, such as the need to support allies through initiatives like Lend-Lease, further shifted the U.S. toward active participation in global affairs. These factors collectively marked a significant shift from a historically isolationist stance to a more engaged international role.