How did the Roosevelt Corollary change U. S foreign policy?

The Roosevelt Corollary to the Monroe Doctrine affirmed the United States new proactive and possibly imperialist stance towards foreign policy and made it so that the US was now going to be involved in the affairs of other countries in the Western hemisphere.

The Roosevelt Corollary in 1904 justfited US intervention in the Western Hemisphere. It was an addition to the Monroe Doctrine which had wanted to prevent European intervention in the West.