A) The Roosevelt Corollary
2) Roosevelt Corollary to the Monroe Doctrine – the Monroe Doctrine warned nations of Europe not to intervene in the affairs of the countries in the Western Hemisphere; Roosevelt extended this principle to justifying the intervention of the United States in the affairs of these countries in order to forestall any actions of “outsiders.” In practice, this led to armed intervention by the United States on a number of occasions.
The Platt Amendment stipulated the conditions for U.S. intervention in Cuban affairs and permitted the United States to lease or buy lands for the purpose of the establishing naval bases (the main one was Guantánamo Bay) and coaling stations in Cuba. It barred Cuba from making a treaty that gave another nation power over its affairs, going into debt, or stopping the United States from imposing a sanitation program on the island. Specifically, Article III required that the government of Cuba consent to the right of the United States to intervene in Cuban affairs for “the preservation of Cuban independence [emphisis mine], the maintenance of a government adequate for the protection of life, property, and individual liberty, and for discharging the obligations with respect to Cuba imposed by the Treaty of Paris on the United States, now to be assumed and undertaken by the Government of Cuba.”
This contrasts with the Teller Amendment, passed before the beginning of hostilities, which claimed that the United States government had no interest in holding any territory that it might gain in concession from Spain.
The Banana Wars--this new interventionist foreign policy led to numerous invasions of foreign countries in Central and South America, as well as several Caribbean islands, to "protect US interests"--business interests, that is
(a) Haiti – protectorate from 1915-1934
(b) Dominican Republic – protectorate 1905-1941; protectorates were nominally independent, although the United States reserved the right to intervene in internal affairs—and prevented protectorates from signing any treaties with third countries (that is, countries other than the United States.
(c) Honduras--the original Banana Republic, so named by US author O. Henry.
War is a Racket, where he claimed
4) Russo-Japanese War – Japanese pushed Russian military around in Asia, eventually occupying Korea.
a) Japan – Japanese desires to become dominant force in Asia collided with US desires for the same; racial animosity also fueled this rivalry