For the past three centuries, Great Britain and the United States have stood in succession at the apex of the international hierarchy of power. They have been on the winning side of every systemic conflict in this period, from the War of the Spanish Succession to the Cold War. As a result, they have been able to influence the political and economic development of states around the world. In many of their colonies, conquests, and clients, they have propagated ideals and institutions conducive to democratization. At the same time, they have defeated numerous rivals whose success would have had ruinous consequences for democracy. The global spread of democracy, therefore, has been endogenous to the game of great power politics.