British Prime Minister David Cameron has announced that a referendum on whether or not the United Kingdom should remain in the European Union will be held on 23 June 2016. The EU rep-resentatives and the British government have been in the negotiations on the EU reforms that London describes as necessary for the UK to remain in the EU. What would the future of Eu-rope and the Union be like in the event that, despite all efforts, the referendum decided that the UK would leave the EU? And what would be the consequences for the Common Foreign and Security Policy (CFSP) and the overall strategic position of the Union? The three most likely scenarios described below, all of which are based on the statements of political leaders, aca-demic texts and statistical data, attempt to answer these questions. All, however, assume that good relations between Brussels and London will be maintained.
According to the first scenario, the Brexit will limit the EU’s military and defensive capabilities. Instead of with defense policy, CFSP will become preoccupied with humanitarian issues, climate change and cross-cultural dialogue. The cooperation in this area will be based on bilateral agreements outside the European Union or within the NATO. In many other areas, ad hoc col-laboration between London and the EU will remain an option.
The second scenario is the possibility of developing a flexible cooperation among the EU Mem-ber States themselves and with other countries. This collaboration will further expand opportu-nities for the third countries for the so-called ‘opt-in’, which is essentially the participation in this kind of cooperation, whereby the conditions for the participation of non-member countries would be finalized during the participation process itself. This process should gradually lead to the creation of the “European Defense Union”, as the European pillar of NATO, which would aspire to include all the current EU Member States.
The last scenario is based on the assumption that the Brexit will remove the main obstacle to closer cooperation within the EU. After the UK has left the EU, the political union will be deep-ened and the “European Defense Union” will be created. A military headquarters will be created in Brussels, decision-making within the CFSP will be improved, regular debate on defense will take place and the budget for foreign operations will be increased. The EU will thus become a significant regional player supplementing the NATO.