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 The troops stationed in Cuba were withdrawn in 1921, but U.S. forces remained in the other three nations throughout Harding's presidency. In April 1921, Harding gained the ratification of the Thomson–Urrutia Treaty with Colombia, granting that nation $25 million (equivalent to $ million in ) 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. The U.S. had intervened repeatedly in Mexico under Wilson, and had withdrawn diplomatic recognition, setting conditions for reinstatement. The Mexican government under President Álvaro Obregón wanted recognition before negotiations, but Wilson and his final Secretary of State, Bainbridge Colby, refused. Both Hughes and Fall opposed recognition; Hughes instead sent a draft treaty to the Mexicans in May 1921, which included pledges to reimburse Americans for losses in Mexico since the 1910 revolution there. Obregón was unwilling to sign a treaty before being recognized, and worked to improve the relationship between American business and Mexico, reaching agreement with creditors, and mounting a public relations campaign in the United States. This had its effect, and by mid-1922, Fall was less influential than he had been, lessening the resistance to recognition. The two presidents appointed commissioners to reach a deal, and the U.S. recognized the Obregón government on August 31, 1923, just under a month after Harding's death, substantially on the terms proffered by Mexico. Domestic policy Postwar recession and recovery When Harding took office on March 4, 1921, the nation was in the midst of a postwar economic decline. At the suggestion of legislative leaders, Harding called a special session of Congress, to convene April 11. When Harding addressed the joint session the following day, he urged the reduction of income taxes (raised during the war), an increase in tariffs on agricultural goods to protect the American farmer, as well as more wide-ranging reforms, such as support for highways, aviation, and radio. It was not until May 27 that Congress passed an emergency tariff increase on agricultural products. An act authorizing a Bureau of the Budget followed on June 10, and Harding appointed Charles Dawes as bureau director with a mandate to