During the early 1920, the U.S rejected to join the League of Nations (that the President Woodrow himself proposed), high tariffs imposed by the Fordney-M Cumber act prevented international trade, and the emergency quota act created barriers for immigration from some countries. All these actions isolated America from International Affairs.
Militia maybe. A militia is a military force that is raised from the civil population to supplement a regular army in an emergency. It is made up of a group of volunteers.
