Various alliances and organizations have contributed to ensuring stability and security in Europe for more than half a century after two devastating wars. The Western European Union (WEU) and the North Atlantic Treaty Organization (NATO) have acted as alliances, while the Organization for Security and Co-operation in Europe (OSCE) has served as a mediator, each motivated by different reasons and mandates. In the future, the European Union itself aims to act as an independent actor with its Common European Security and Defence Policy (CSDP). Thomas Schneider examines the history, organization, and potential impact of the various players and concludes: The success of security organizations heavily depends on the willingness of their members – as independent actors, they are therefore only limited in their ability to act. Consequently, Europe's future cannot be guaranteed by a single institution. A cooperative approach in European security policy offers many advantages in this regard. In any case, political instruments must take precedence over military interventions to ensure lasting peace in Europe.