Sea Change: McKinley, Roosevelt, and the Expansion of U.S. Foreign Policy 1897-1909

Abstract

For U.S. foreign policy, the long decade of 1897-1909 was one of the most consequential eras in U.S. history. The United States was vastly expanding its involvement in the world. It acquired several overseas territories, established a large presence in the Pacific, brought down a European power, deployed thousands of troops to fight wars in Asia for the first time, began building an interoceanic canal, consolidated its power over the Caribbean, tripled the size of its military, and deepened its diplomacy outside of the Western hemisphere. This dissertation explains why by analyzing six major presidential decisions of William McKinley and Theodore Roosevelt: the annexation of Hawaii, the pursuit of war against Spain, the annexation of the Philippines, intervention in Panama, hosting the Portsmouth Peace Conference, and supporting and negotiating the Algeciras Conference. In doing so this dissertation proposes and applies a new interdisciplinary method for explaining historical decisions, drawing from history, international relations, and decision science. It categorizes explanatory factors into two groups: “decision-generating factors” (the forces that enabled and put the decision on the policy agenda) and “decision-making factors” (the forces that swayed the president’s mind). Within those categories, factors are further labeled “first order” and “second order” to signify the degree of influence. Those are then ranked. This method allows one to compare how various factors mattered in a decision, and to what degree. The primary findings are that systemic political forces, like U.S. power and geography, tended to be the most important decision-generating factors. Events were mostly of secondary importance, affecting the timing and expression of the decision point. Once the decision point arose, McKinley and Roosevelt mattered greatly as leaders. Their choices are explained as much by their interpretation of broader social and political forces as by their peculiar psychologies, like their morality. McKinley emerges as an overlooked leader of U.S. foreign policy. His decisions were more consequential than Roosevelt’s, though they each left their own significant mark in history. This study is the first pairwise, volume-length analysis of the foreign policies of McKinley and Roosevelt.