A good piece of evidence to examine when studying Theodore Roosevelt's foreign policy would be the so-called Roosevelt Corollary. This was a policy that stated that the United States would get involved as a mediator whenever any European power tried to press claims of sovereignty in the Americas. As such, he was extending the Monroe Doctrine to state that the United States would act as the international police force of the hemisphere. Roosevelt invoked the Corollary to intervene in the Dominican Republic in 1904.

Roosevelt's foreign policy also involved what is known as Big Stick diplomacy. This required the United States to have a large military presence that could be quickly and decisively deployed around the world. This would intimidate any would-be adversary into compliance. It also required using that force as promised when needed. Despite having the power to crush opponents, Roosevelt wanted to allow them to be able to concede with honor. This policy was deployed when the US intervened to allow Panama to rebel against Colombia.

Overall, Roosevelt wanted to fully take the country out of its long history of isolationism and make it a world power like the mightiest nations of Europe. He became the first sitting president to ever travel overseas when he visited the canal construction project in Panama. He also used his position as an international peacemaker. For instance, he brokered peace between Russia and Japan in 1905 and worked to calm tensions between France and Germany over claims in North Africa. All this indicated to the other world powers that the United States had fully entered the world stage.