 The U.S. had considerable business interests in Mexico, especially oil, and the threat of Mexican economic nationalism to big oil companies meant that diplomatic recognition could hinge on Mexican compromise in implementing the constitution.In 1923 when the Mexican presidential elections were on the horizon, Obregón began negotiating with the U.S. government in earnest, with the two governments signing the Bucareli Treaty.The treaty resolved questions about foreign oil interests in Mexico, largely in favor of U.S. interests, but Obregón's government gained U.S. diplomatic recognition.