In a mere fifty years, the United States transformed itself from a second-tier country crippled by its effort to abolish the appalling institution of human slavery into a great power unlike any the world had ever seen. The question of how it did this should command our attention all by itself, but the question of why it became such a peculiar—and incompetent—empire surely ranks as one of the great questions of modern history. For truly, measured by consequences, few global disasters can match the mismanagement of the international system in the 1920s, which owed almost entirely to bad decisions made in America. All that saves the United States from complete responsibility is the answer to the first question, of how this change happened so fast: America became a great power so swiftly, and became such a peculiar empire, because the rest of the world made it that way.
