In the past ten years NATO has developed its operations inside and outside Europe. Since Cyprus joined the EU in 2005, the ongoing dispute between Turkey (a non-EU NATO member) and Cyprus (a non-NATO EU Member State) has hindered any further cooperation between the two organisations in the ‘Berlin Plus’ format. As a result, NATO and the EU have learned to cooperate informally. While there has been no formal cooperation in the context of ‘Berlin Plus’ since 2004, the EU and NATO regularly rely on informal cooperation when operations coincide. This has been the case in Kosovo, Afghanistan, the Horn of Africa and most recently in the Mediterranean Sea.