Intervention in Latin America had been a minor campaign issue; Harding spoke against Wilson's decision to send U.S. troops to the Dominican Republic, and attacked the Democratic vice presidential candidate, Franklin D. Roosevelt, for his role in the Haitian intervention. Secretary of State Hughes worked to improve relations with Latin American countries who were wary of the American use of the Monroe Doctrine to justify intervention; at the time of Harding's inauguration, the U.S. also had troops in Cuba and Nicaragua. The troops stationed in Cuba to protect American interests were withdrawn in 1921, but U.S. forces remained in the other three nations through Harding's presidency. In April 1921, Harding gained the ratification of the Thomson–Urrutia Treaty with Colombia, granting that nation $25,000,000 as settlement for the U.S.-provoked Panamanian revolution of 1903. The Latin American nations were not fully satisfied, as the U.S. refused to renounce interventionism, though Hughes pledged to limit it to nations near the Panama Canal and to make it clear what the U.S. aims were.