Using the example of the European People’s Party’s (EPP) activities in the Ukraine, Moldova and Georgia, this book demonstrates that European political parties may, under certain conditions, successfully influence political party transformation in the Eastern European Neighbourhood. In order to cover the highest possible variety of interactions between the EPP and its partner parties, the study examines three different mechanisms of norm promotion: conditionality, persuasion and social influence. While the EPP has influenced its partner parties to a certain extent both on an internal and an external level of party development, certain features of its partner parties have, however, strongly limited its influence, and its partner parties have often been resistant to change. Equally, their compliance with the EPP has frequently been merely rhetorical or formal. Finally, the author suggests a typology of which type of partner parties has been more likely to demonstrate such compliance.