U.S. policy toward Latin American policy involved a significant revision of the Monroe Doctrine. Throughout the 19th century, American diplomats used the Monroe Doctrine to warn the European powers against further colonization in the Western Hemisphere. It did not imply the right of the United States to intervene in the internal affairs of the other American republics.
President Theodore Roosevelt
In 1904, President Theodore Rooseveltchanged the Monroe Doctrine through his “Roosevelt Corollary.” Roosevelt and other prominent Americans were concerned that European creditor nations would use the unpaid debt of the Latin American states to gain political control over them. Roosevelt said that no Latin American nation adhering to “acceptable international standards of behavior” had to fear intervention by the United States. But: “Chronic wrongdoing, or an impotence which results in a general loosening of the ties of civilized society, may in America, as elsewhere, require intervention by some civilized nation.”
Moreover, he continued, “in the western hemisphere the adherence of the United States to the Monroe Doctrine may force the United States, however reluctantly, in flagrant cases of such wrongdoing or impotence, to the exercise of an international police power.”
At the same time, the acquisition of the Philippines triggered the development of a new American policy for East Asia. As American businessmen eyed the vast potential of the Chinese market, European incursions in China threatened to cut off American access. In 1899, Secretary of State John Hay proposed that nations interested in China should “enjoy perfect equality of treatment for navigation,” that is, maintain the principle of free trade, or the “open door.” In 1900, Hay extended the open-door policy to include respect for the territorial and administrative integrity of China.