The league of nations was less than effective for all of the following reasons except

a.) the united states did not join.
b.) the united states did not ratify the treaty of versailles.
c.) league members could not agree to use force against aggression.
d.) president wilson did not support the idea.

The League of Nations was less than effective for all the following reasons:
A. The United States did not join.
B. The United States did not ratify the Treaty of Versailles.
C. League members could not agree to use force against aggression.

The League of Nations on the other hand was not less than effective because of President Wilson did not support the idea. The answer would be letter D.

The correct answer is b