In 2014, Russia illegally annexed Crimea, bolstered a separatist conflict in the Donbas region, and attacked Ukraine with its regular army and special forces. In each instance of Russian aggression, the U.S. response has often been criticized as inadequate, insufficient, or hesitant. The Moscow Factor: U.S. Policy toward Sovereign Ukraine and the Kremlin is a unique study that examines four key Ukraine-related policy decisions across two Republican and two Democratic U.S. administrations. Eugene M. Fishel asks whether, how, and under what circumstances Washington has considered Ukraine’s status as a sovereign nation in its decisionmaking regarding relations with Moscow. This study situates the stance of the United States toward Ukraine in the broader context of international relations. It fills an important lacuna in existing scholarship and policy discourse by focusing on the complex trilateral—rather than simply bilateral—dynamics between the United States, Ukraine, and Russia from 1991 to 2016. This book brings together for the first time documentary evidence and declassified materials dealing with policy deliberation, retrospective articles authored by former policymakers, and formal memoirs by erstwhile senior officials. The study is also supplemented by open-ended interviews with former and returning officials.