President Roosevelt wanted to take a more active and progressive role in the Americas.
He "amended" the Monroe doctrine and added the Roosevelt Corollary. This asserted the right of the United States to intervene in the affairs of Caribbean and South American nations if it deemed necessary. This paved the way for intervention in other sovereign nations, notably Cuba and the Dominican Republic. Projects such as the Panama Canal rose out of his policy. The United States intervened and aided the Panama revolution, so it could be its own country and be the location of the canal. Such interventions were justified by the Roosevelt
Corollary. Roosevelt believed in the proverb "speak softly and carry a big stick." This is most evident in his great white fleet. As the president's administration began to end he sent out a fleet which contained four battleship squadrons on a cruise around the world. This was known as the Great White Fleet, as all of the hulls of the ships were painted white. He wanted to demonstrate that the United States was a world power. The fleet sailed at a time when tensions were rising between Japan and the US. This eventually led to increased Japanese efforts to build a stronger nave leading up to World War Two. President Roosevelt wanted to show that America was a powerful force and that they would use their force.
During Roosevelt's administration the United States took a more active role in the affairs of the world. Through shows of force and intervention in the affairs of others, the foreign policy of the United States was greatly altered. The United States had previously been an isolated Nation and was now taking an active role in other nations.