In what way did Theodore Roosevelt greatly influence America's change from isolationism?

The United States became allies with Japan in the Russo-Japanese War ... He was the leader when the United States was an industrial and agricultural success.

The correct answer is C) he participated in world-wide events like the Panama Canal and international peace settlements.

The other options of the question were A) The United States became allies with Japan in the Russo-Japanese War. B) Roosevelt did tremendous improvements in forest conservation in the US. D) he was the leader when the US was an industrial and agricultural success.

Theodore Roosevelt greatly influenced America's change from isolationism because he participated in world-wide events like the Panama Canal and international peace settlements.

Roosevelt believed that the United States should have more participation in the international scene and be able to defend its economic and political interests. He authored the "Roosevelt Corollary" to the Monroe Doctrine to let European Nations that the US would intervene in Latin American issues, to avoid the direct intervention of European superpowers.