The U.S. had asserted that it had the preeminent role in the Western hemisphere, with U.S. President Theodore Roosevelt modifying the Monroe Doctrine via the Roosevelt Corollary, which declared that the U.S. could intervene in other countries' political affairs if the U.S. determined they were not well run. Díaz pushed back against this policy, saying that the security of the hemisphere was a collective enterprise of all its nations. There was a meeting of American states, in the second Pan-American Conference, which met in Mexico City from 22 October 1901 – 31 January 1902, and the U.S. backed off from its hard-line policy of interventionism, at least for the moment in regard to Mexico.