How did the isolationist actions of the us affect lasting peace in europe after world war i? without us support, the league of nations weakened significantly. without us , european nations could not prevent use of military force. without us , secret military alliances no longer took place. without us support, european countries did not ratify the treaty of versailles.

The isolationism that set in the U.S. after the end of World War I had two negative effects on the capability of the League of Nations to enforce peace and settle international conflicts during the postwar years: the League of Nations could not prevent the use of military force by European nations and was so weak that it was unable to enforce embargos on aggressive nations. The absence of a representative of the U.S. before the League of Nations wrestled a great deal of respectability and political and military power.

i think your answer is c.

i think.

sorry if its wrong!