PESCO as a Game-changer for Differentiated Integration in CSDP After Brexit

Resumen

After decades of bi-national and multinational military programmes that arrived in dribs and drabs, and once the United Kingdom decided to withdraw from the EU, the launch and implementation of the Permanent Structured Cooperation (PESCO) in 2017 has emerged as a real game-changer. Thus, favouring differentiated integration in defence matters within the European Union after Brexit. This Article focuses on the analysis of both horizontal and vertical differentiated integration from an eminently practical point of view. All of this, aimed at illustrating the distinction between the pre-PESCO scenario and the current one with 60 projects underway within its framework. In this sense, the analysis makes it possible to distinguish a real group of frontrunners in the implementation of PESCO and the window of opportunity that opens up by allowing third states to participate in individual projects, with particular attention to the case of the United Kingdom.