Enlargement is often considered to be the strongest foreign policy tool available to the European Union, and is instrumental in the EU’s efforts to spread its liberal democratic norms in the post-communist countries of Central and Eastern Europe. However, the experience of recent years has painted a more uneven picture. While the EU’s norms have proven to be reasonably robust in countries such as Czechia, in others, most notably Hungary, they have proven to be far more fragile. What accounts for this post-accession variation in adherence to liberal democratic norms between the post-communist Central and Eastern European Countries? And what implications does this have for the use of enlargement policy as a means for spreading democracy? This book explains the processes and mechanisms which determine how the liberal democratic norms of the European Union can be transferred to another country; and why enlargement has had such mixed results to date.