ABSTRACT
This article discusses evolving patterns of internal security cooperation that start in the realm of international public law and end up more or less entirely in the treaty framework of the European Union. By applying the theory of clubs (Buchanan) it shows the fertility as well as limitations of a public goods approach to analyse and explain such instances of differentiated integration and to assess their effectiveness. By way of the comparative analysis of the Schengen regime and the Prüm Treaty it analyses five main stages of an internal security club’s life circle from the causing obstacle (blocking of a certain policy) to the final incorporation endgame. Both clubs under investigation produced so-called network goods with negative rivalry logic, i.e. the more members participate and ‘consume’ the good the higher the benefit for all. However, it is also shown that club formation and expansion could not only be understood as a strategically rational process, and that various contextual costs inhibited the formation and eventual expansion of the clubs. The article concludes that incorporation efforts necessarily lead to pick-and-choose situations that preclude full uniformity; consequently, outside treaty clubs tend to create á la carte fragmentation to a certain degree.
