The large objection to the League of Nations that the isolationists in Congress had was that they thought the US was being hurt by the deal and giving up sovereignty. They were concerned that membership in the League would commit the United States to foreign conflicts and entanglements, and that it would undermine the country's ability to act independently in its own interests. They saw the League as a threat to American sovereignty and feared that it would drag the United States into wars that were not in its best interest. This view was reflected in the Senate's rejection of the Treaty of Versailles, which included membership in the League, in 1919.