U.S. foreign policy toward Latin America in the 19th century initially focused on excluding or limiting the military and economic influence of European powers, territorial expansion, and encouraging American commerce. These objectives were expressed in the No Transfer Principle (1811) and the Monroe Doctrine (1823). American policy was unilateralist (not isolationist); it gradually became more aggressive and interventionist as the idea of Manifest Destiny contributed to wars and military conflicts against indigenous peoples, France, Britain, Spain, and Mexico in the Western Hemisphere. Expansionist sentiments and U.S. domestic politics inspired annexationist impulses and filibuster expeditions to Mexico, Cuba, and parts of Central America. Civil war in the United States put a temporary halt to interventionism and imperial dreams in Latin America. From the 1870s until the end of the century, U.S. policy intensified efforts to establish political and military hegemony in the Western Hemisphere, including periodic naval interventions in the Caribbean and Central America, reaching even to Brazil in the 1890s. By the end of the century Secretary of State Richard Olney added the Olney Corollary to the Monroe Doctrine (“Today the United States is practically sovereign on this continent and its fiat is law upon the subjects to which it confines its interposition . . .”), and President Theodore Roosevelt contributed his own corollary in 1904 (“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 wrongdoing or impotence, to exercise an international police power”). American policy toward Latin America, at the turn of the century, explicitly justified unilateral intervention, military occupation, and transformation of sovereign states into political and economic protectorates in order to defend U.S. economic interests and an expanding concept of national security.
From 1800 to the present, US troops have intervened thousands of times in Latin America and have occupied its countries on dozens of occasions. Interventions were short-term and superficial, while occupations lasted longer and controlled local governments. The causes of these troop landings reflected the United States’ motivations as it expanded from a strong, large republic into first a continental and then an overseas empire at the expense of its smaller, weaker neighbors. Those motivations included colonial land hunger, cultural chauvinism, the exploitation of resources, the search for markets abroad, competition against other great powers, political reformism, global ideological struggle, and the perception that US domestic problems originated in Latin America. US troops undertook almost all these interventions and occupations, although private groups sometimes joined. The major periods were the expansion of the continental republic from 1811 to 1897, the war in Cuba and the apex of occupations (1898–1933), the Good Neighbor years (1934–1953), the Cold War (1954–1990), and the post-Cold War period (1991–2018 and ongoing). Scholars of these events have become increasingly critical and diverse, not only seeing them often as unnecessary brutal failures but also foregrounding extra-military aspects of these episodes, such as economics, race, and gender.