- The Neutrality Acts: In the 1930s, the United States passed a series of Neutrality Acts that prohibited the sale of arms to belligerents in a war and forbade American citizens from traveling on ships of belligerent nations. These acts made it difficult for the United States to provide assistance to countries that were fighting against Nazi Germany, such as Great Britain and France.
- The Nye Committee: The Nye Committee was a special committee of the United States Senate that investigated the munitions industry in the 1930s. The committee's findings, which were published in 1936, suggested that the arms industry had played a role in starting World War I and that the United States should avoid involvement in future wars. This report reinforced the isolationist sentiment in the United States and made it more difficult for the government to take action against Nazi Germany.
- The America First Committee: The America First Committee was a political organization that opposed United States involvement in World War II. The committee argued that the United States should focus on its own domestic problems and avoid becoming entangled in foreign conflicts. The America First Committee had a significant following in the United States, especially in the Midwest, and it helped to keep the country out of the war until after the attack on Pearl Harbor.
In conclusion, isolationist policies in the United States contributed to the outbreak of World War II by preventing the United States from taking action to prevent the rise of Nazi Germany.