"Completes the magisterial reexamination begun in Quest for equilibrium, of the sources, precedents, and continuing predicaments of the United states at the outset of the third century of national involvement in world affairs ... Portrays the external, domestic, politico-military, and economic factors that propelled Americans from its earliest colonial beginnings into fitfully continuing expansion ... [These factors] both aided and hampered the United States in the organization and defense of what eventually became a worldwide empire"--Jacket.