This book explores how Iran has come to occupy a uniquely antagonized position in US foreign policy by tracing the role of a dominant pro-Israel identification within American policymaking. It argues that hostility toward Iran is not simply the result of strategic calculations or historical grievances, but is deeply shaped by an internalized understanding of what it means to be “pro-Israel” in Washington—a stance increasingly tied to American political identity itself. Within this framework, identifying Iran as a threat becomes a central, often unquestioned, component of expressing political credibility and belonging. By analyzing how this pro-Israel identification has been constructed, institutionalized, and linked to the portrayal of Iran as an existential adversary, this book reveals how US policymakers are routinely confronted with a constrained policy field. The identification of Iran as a threat is not merely encouraged but expected, with alternative approaches often framed as incompatible with American or pro-Israel commitments. The result is a binary logic: to support Israel is to oppose Iran, limiting the space for dissent or diplomatic engagement. This book will be of interest to scholars and students of US foreign policy, Middle East politics, and identity-based policymaking, as well as journalists and analysts focused on US– Iran– Israel relations.