The Isolationist policy of the United States was a long-lasting ideal reaching back to before World War One. Woodrow Wilson's 1916 re-election campaign was based on the motto "he kept us out of the war". Prior to joining the war, the United States made considerable amounts of money by producing weapons to sell to the Allied forces. However, this wealth was not shared by other countries involved in the war. In fact, many countries relied on loans from the United States during and after the war.

When Woodrow Wilson made his speech to Congress outlining his aims for a peace settlement and later suggested his 14 Points model to the 'Big Four', there was great dissention from both the European and American parties. European parties felt that the 14 points were too idealistic, whereas American parties did not want to have any future part in the outcomes of Europe. Many Americans even felt that they did not need the rest of the world, that the United States could plot their own destiny without considering others. This opinion was reinforced by a dissention speech made by Henry Cabot Lodge to Senate on the 12th of August, 1919. In his speech, Cabot Lodge shared his suspicions of involving the United States unnecessarily in international affairs. This viewpoint ended up becoming the majority opinion over that of the continuously ailing president.

Despite their reluctance to become involved in Europe politically, the United States played a heavy role in the economic matters of many countries in Europe, including Germany's hyperinflation. In 1924, the Dawes Plan provided loans from American banks in order to stabilize the German economy and scale down reparations while effectively encouraging French withdrawal from the Ruhr. President Hoover was also responsible for the one year moratorium on reparation payments due to worldwide economic problems and finally, in 1932 at Lausanne, European powers agreed to reduce Germany's reparations, but only if the United States would do the same for them.

The United States was also deeply involved in disarmament talks such as the Washington Naval Conference of 1921. This treaty froze the number of ships owned by countries for 10 years at the ratio of 5 each for the United States and Britain, 3 for Japan and 1.75 for Italy and France. This was a controversial success for the United States as it was able to avoid political entanglements while still retaining its superiority over Japan. This conference appeared to promote peace and stability; however both Japan and France were unwilling to subvert their power. This created a growing threat of Japanese expansion in Asia, due to their discontent. The London Naval Conference of 1930 appeared to quell this discontent, however Japans invasion of Manchuria proved otherwise.

The United States put harsh tariffs in place that made it very difficult for countries to trade with the United States. They were able to by American goods, however the tariffs made it very expensive for American companies and citizens to buy goods from around the world, which further worsened their economies. On May 26, 1924, the American government put strict immigration policies in place under the Immigration Act of 1924, or the Johnson-Reed Act, allowing for an annual immigration limit of only 2% of the nationals of a given country resident in America in 1890. This specifically limited the immigration of Catholics, Jews and Asians, who immigrated mostly after 1890. This encouraged British, German and Scandinavians to immigrate to the United States, who were in large numbers in the United States before 1890.

Although the United States isolated itself politically from Europe and the rest of the world, it still fought to remain connected through disarmament treaties, tariffs, immigration policies and economic dealings worldwide.

Time line:

  • June 28, 1914: Great War Starts.
  • April 2, 1917: Woodrow Wilson suggests joining WWI in speech to Congress
  • April 6, 1917: US declares war on Germany
  • December 7, 1917: US declares war on Austria-Hungary
  • January 8, 1918: Woodrow Wilson outlines aims for peace settlement in speech to Congress
  • January 18, 1919: Peace negotiations start in Paris
  • April 1919: Covenant of the League of Nations approved
  • June 1919: Wilson signs Anglo-American guarantee for France, despite Senate opposition
  • August 12, 1919: Henry Cabot Lodge objects to joining League of Nations in speech to Senate
  • March 19, 1920: Senate refuses ratification of the Treaty of Versailles
  • February 1921: US withdraws representative from the Reparations Commission
  • March 4, 1921: Woodrow Wilson not re-elected
  • August 1921: US signs separate peace treaty with Germany
  • 12 November, 1921-6 February, 1922: Washington Naval Conference
  • May 26, 1924: Immigration Act of 1924, or the Johnson-Reed Act, signed by Calvin Coolidge
  • August 16, 1924: Dawes Plan adopted
  • June 16-July 9, 1932: Lausanne Conference
  • December 7, 1941: Pearl Harbor causes the US to join WWII, forcing the US to abandon their isolationist policy