Contents

1. Introduction
2. Differentiated Integration in the EU
3. Schengen
4. The Treaty of Prüm
   4.1. The way to the Prüm Treaty
   4.2. The contents of the Prüm Treaty
   4.3. Ratification, Entry into Force and Integration into the EU Legal Framework
5. Analysis of the Prüm Treaty
   5.1. Comments from Researchers
   5.2. Comments by the European Data Protection Supervisor
6. Concluding Remarks