The Western Balkans have seen rapid changes since the end of the violent conflicts in the 1990s. The European Union (EU) has been one of the main drivers for change, focusing on the political, economic and social transformation of the region to prepare the countries for membership in the Union. This introduction to the special issue will clarify the key terms and their interaction in the Western Balkans. EU enlargement has never before been this complex and inter-connected with processes of state-building and democratization. The focus on conditionality as the main tool of the EU in the region has had positive and negative effects. It can be argued that the EU is actively involved in state-building processes and therefore the term EU Member State Building will be used to explain the engagement of the Union with the countries in the region. This paper will discuss the concept of EU Member State Building, its potential and its pitfalls. It will be demonstrated that the stabilization of the region is unlikely to take place without an active role for the EU; however, the current approach has reached its limits and it is time to think about alternative options to integrate the Western Balkans into European structures.