This introduction outlines some of the main topics in the history of American foreign relations. It explains the importance of seven key themes—moral values; a belief in expansion and progress; racial and religious norms; the centrality of war; the influence of geography; the myth of “isolationism”; and domestic politics—in how Americans have interacted with the rest of the world. These themes are useful signposts to understanding an otherwise complicated history. The Introduction aims to explain these themes in as even-handed a manner as possible. In this way, readers will be able to address some of the most important topics and lay to rest some of the most common myths about America in the world.