Can the West promote democracy? An examination of one critical case, the 2004 Orange Revolution in Ukraine, offers a unique method for generating answers to this important theoretical and policy question. Tracing the causal impact of external influences first requires a theory of democratization composed exclusively of domestic factors, specifically the changing distribution of power between the autocratic regime and democratic challengers. Once these internal factors have been identified, the extent to which external factors influenced either the strength of the autocratic regime or the democratic challengers can be measured. Domestic factors accounted for most of the drama of the Orange Revolution, but external factors did play a direct, causal role in constraining some dimensions of autocratic power and enhancing some dimensions of the opposition's power. International assistance in the form of ideas and financial resources was crucial to only one dimension of the Orange Revolution: exposing fraud. Yet significant international inputs also can be identified regarding the preservation of semi-autocracy, the nurturing of an effective political opposition, the development of independent media, and the capacity to mobilize protesters after the falsified presidential vote.