Theodore Roosevelt

Theodore Roosevelt (1858–1919) served as the 26th President of the United States from 1901 to 1909, assuming office after the assassination of William McKinley. A Republican from New York, he reshaped both the American presidency and U.S. foreign policy, championing an assertive, interventionist posture that became known as "big stick diplomacy" — drawn from his phrase, "speak softly and carry a big stick."

In international relations, Roosevelt is most studied for:

• The Roosevelt Corollary to the Monroe Doctrine (1904), which asserted a U.S. right to intervene in Latin American states experiencing "chronic wrongdoing" to preempt European intervention. It justified later U.S. interventions in the Dominican Republic, Cuba, and Nicaragua.
• The Panama Canal: after Colombia rejected the Hay–Herrán Treaty, Roosevelt supported Panamanian independence in 1903 and secured the Hay–Bunau-Varilla Treaty granting the U.S. canal-zone rights. Construction began under his administration.
• Mediation of the Russo-Japanese War, producing the Treaty of Portsmouth (1905), for which Roosevelt received the 1906 Nobel Peace Prize — the first awarded to a sitting head of government.
• The Great White Fleet (1907–1909), a global circumnavigation by U.S. battleships demonstrating American naval power.
• Participation in the Algeciras Conference (1906) over Morocco, helping defuse a Franco-German crisis.

Domestically, Roosevelt advanced the Square Deal, antitrust enforcement (notably against Northern Securities), railroad regulation through the Hepburn Act (1906), and large-scale conservation, creating numerous national forests, monuments, and the U.S. Forest Service.

After leaving office, he led the Progressive ("Bull Moose") Party in the 1912 election, splitting the Republican vote and enabling Woodrow Wilson's victory. He later urged U.S. entry into World War I.

For MUN and IR students, Roosevelt is a canonical case study in realist statecraft, hemispheric hegemony, and the transition of the United States into a great-power role at the turn of the 20th century.