When compared to the United Nations, one of the main reasons the League of Nations was unable to fulfill its purpose was that the United States was not a member.
While the League of Nations was proposed by the U.S. President Woodrow Wilson, Congress voted that the US would not take part of the League of Nations. On the other hand, the U.N. was set up by Franklin D. Roosevelt, and the U.S continue to play a major role in the alliance.
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