What conflict did Roosevelt help to resolve, earning him the Nobel Peace Prize?

The appropriate choice is the Russo-Japanese War, which took place from 1904 to 1905. President Theodore Roosevelt played a significant role in mediating peace negotiations between the two countries, which were engaged in a conflict over imperial ambitions in East Asia. With Japan and Russia locked in a fierce struggle, Roosevelt hosted peace talks in Portsmouth, New Hampshire, resulting in the Treaty of Portsmouth in 1905. His successful mediation not only brought an end to the war but also marked the first time in history that a Western power had recognized Japan as a rising military power.

This diplomatic achievement earned Roosevelt the Nobel Peace Prize in 1906, making him the first sitting American president to receive this prestigious honor. His efforts were indicative of his belief in speaking softly yet carrying a big stick, as he aimed to expand American influence while promoting stability in international relations.