This chapter explores the oscillation in US foreign policy between engagement and restraint, analyzing its historical patterns and ideological underpinnings. It critiques traditional approaches to understanding this phenomenon, including normative, historical, and systemic lenses, and develops a classification of America’s foreign policy streams, which are distinguished by the degree of her active engagement in world affairs. The chapter introduces a taxonomy of US foreign policy factions—Revolutionaries, Reformers, Stabilizers, and Minimalists, highlighting their differing objectives and strategies. It examines the debate between Maximalists, who advocate for active global engagement, and Minimalists, who favor retrenchment, addressing challenges such as hegemonic fatigue and engagement sustainability. Additionally, it discusses the role of partisanship, ideological divisions, and emerging trans-ideological alliances, emphasizing the importance of agency in shaping America’s strategic posture amid global uncertainty.