Answer:
He refused to compromise on his idea for the League of Nations
Explanation:
With the end of World War I, the world witnessed an unprecedented devastation throughout history. In order to fulfill their imperialist intentions, the most powerful nations in Europe have engaged in a conflict causing hundreds of thousands of deaths. Observing this picture of great destruction, much was wondered if this bloodshed would have been worth it.
In 1918, then-President of the United States, Woodrow Wilson, made a proposal that aimed to settle the question definitively. For him, it was more important to seal peace and prevent another war than to point out punishments for losers and compensations for winners. That is why he created a treaty where nations should no longer sign diplomatic agreements that are not publicly recognized. In addition, the treaty believed that free navigation and deliberate trade between nations should strengthen the international link and cooperation. As far as militarism was concerned, it believed that military apparatus should be restricted only to what was necessary for the maintenance of national security.
Wilson was praised for the proposal that was part of the concept for the creation of the united nations league. However the treaty failed to be approved by the US Senate. This is because, according to the Senate, Wilson's proposal would be deviating from his traditional US foreign policy, and thus vetoed his country's entry into the League of Nations and overturned Wilson's proposed treaty.