As the United States has grown from a regional powerhouse to a global superpower, it has continued to maintain the political arrangements, along with the social and cultural traditions, that prevailed in a time of diplomatic detachment. Specifically, early American leaders developed a code of moral, political, and social exceptionalism, while seeking to protect the nation from global entanglements. This approach ultimately set the new nation on a paradoxical course in global relations. Indeed, its ongoing promotion of democratic reforms in foreign countries contributed to a “constitutional” order after World War II that, by the twenty-first century, was widely seen as threatening national sovereignty and as an unacceptable constraint on the nation’s freedom of action. Meanwhile, the nation’s record as a catalyst for economic globalization affirmed one of its founding ambitions but fueled the rise of economic competitors, particularly in the area of industrial production.

This chapter thus explores the paradox of American power in two distinct historical periods. The first begins with the nation’s founding and extends through World War I, during which the United States charted a course of unilateral action, avoiding diplomatic entanglements with the great powers of Europe while building an industrial economy that would make the United States a major force in global trade markets. This period witnessed tremendous territorial expansion along with the exercise of regional power politics as the United States sought to carve out its own sphere of influence in Latin America while alleging it was charting a new course distinct from the imperialism of classic European power politics. In short, with the acquisition of the Louisiana Territory from France, followed by the displacement of Spain from Florida, the subsequent demise of the Spanish empire in Latin America, and the favorable resolution of lingering trade and territorial difference, with Great Britain in the War of 1812, the United States was free to exercise regional hegemony—that is, external dominance without formal political authority. In 1823, to cement this new state of affairs while discouraging any would-be competitors from intruding upon its sphere of influence, President James Monroe proclaimed the Monroe Doctrine, politically separating the United States from Europe and declaring future colonization in the Western Hemisphere a threat to U.S. national security.

The second period covers the conduct of U.S. foreign policy once the country became a great power in the twentieth century. The United States began the century in the midst of a struggle to colonize the Philippines and then asserted hegemonic control over Central America. Emerging from the world wars with unprecedented military strength and economic clout, U.S. leaders then became engulfed in the Cold War with the Soviet Union and other communist states. The Soviet Union’s collapse in 1991 left the United States in the position of unprecedented global primacy. Even so, maintaining this status proved more difficult than expected as regional conflicts and civil wars ignited in many parts of the world. The United States found that even after the end of the Cold War, ethnic and religious conflicts, along with global terrorism, present problems for the “new world order.”

The terrorist attacks on the United States in September 2001 literally brought these conflicts home, shattering the nation’s historic sense of invulnerability, and ushering in a protracted war on terror. In spite of ending the Iraq war in 2011, capturing and killing Osama bin Laden, and significantly reducing the number of U.S. troops in Afghanistan, the Obama administration has continued to face challenges with violent extremist groups such as the Islamic State of Iraq and Syria (ISIS), as well as ongoing democratic revolutions in the Middle East and North Africa. The resurgence of power politics and the actions of Russia and China add another layer of complexity to the U.S.’s ongoing efforts to maintain its primacy.

In order to understand the actors and institutions in the U.S. foreign policy process, this chapter considers how they were created and how they evolved over the years. Actors and institutions are often slow to change in the sense that foreign policies are difficult to revise and implement because of historical inertia and the setup of the U.S. government. The history of U.S. foreign policy, while short, encompasses changing global environments, institutions, and actors that will be discussed in the following chapters.