Although not an isolationist, he was reluctant to enter into European involvements.[146] While Coolidge believed strongly in a non-interventionist foreign policy, he did believe that the United States was exceptional.[147]
Coolidge considered the 1920 Republican victory as a rejection of the Wilsonian position that the United States should join the League of Nations.[148] Coolidge believed the League did not serve American interests.[148] However, he spoke in favor of joining the Permanent Court of International Justice (World Court), provided that the nation would not be bound by advisory decisions.[149] In 1926, the Senate eventually approved joining the Court (with reservations).[150] The League of Nations accepted the reservations, but it suggested some modifications of its own.[151] The Senate failed to act and so the United States did not join the World Court.[151]
Coolidge authorized the Dawes Plan, a financial plan by Charles Dawes, to provide Germany partial relief from its reparations obligations from World War I. The plan initially provided stimulus for the German economy.