For two hundred years, Americans have believed that they have an obligation to improve the lot of humanity, a belief that has consistently shaped U.S. foreign policy. Yet within this consensus, there are two competing schools of thought: the "exemplarist" school (Brands' term) which holds that what America chiefly owes the world is the benign example of a well-functioning democracy, and the "vindicationist" school which argues that force must sometimes supplement a good example. In this book, H.W. Brands traces the evolution of these two schools as they emerged in the thinking and writing of the most important public thinkers of the past two centuries.