Ever since the launch of the EU’s Common Security and Defence Policy, the question of the relations between NATO and the EU is at the core of the debate on European defence. Given their large overlap in membership, cooperation between both organisations has often been seen as a natural development. In 2003, the so-called “Berlin Plus” arrangements allowed the EU to make use of NATO assets and capabilities for EU-led military operations. More recently, in July 2016, the Presidents of the European Council and the Commission as well the NATO Secretary General signed a Joint Declaration aimed at strengthening coordinated action between both organisations. However, in practice, EU-NATO cooperation has often been hindered by factors such as the Atlanticist-Europeanist divide or tensions between Turkey and Cyprus. Over the last couple of years, transatlantic relations have been tested by the election of Donald Trump, and the Brexit referendum has initiated the departure of one of the EU’s most pro-NATO member-states. In addition, recent EU defence cooperation initiatives such as the European Defence Fund proposed by the European Commission and the Permanent Structured Cooperation, launched by 25 member states, have revived fears of inter-organisational duplication and rivalry, as well as anxiety among non-EU NATO member states. This Conference seeks to foster the debate on recent and future developments of EU-NATO relations by exploring practical interactions on the ground as well as broader political issues.