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UK–France Combined Joint Expeditionary Force

Brexit and European Security

Malcolm Chalmers
Briefing Papers, 26 February 2018
European Union
RUSI Deputy Director-General Malcolm Chalmers looks at the security implications for the UK and Europe post-Brexit.

The UK’s vote to leave the EU was not primarily about security. But it could have serious consequences for future security cooperation between the UK and its European neighbours. Prime Minister Theresa May made it clear in her speech to the Munich Security Conference on 17 February that she wanted to build a ‘deep and special partnership’, which will allow the UK and the EU to ‘retain the cooperation that we have built and go further in meeting the evolving threats that we face together’. Achieving this objective will not be straightforward, and will require a strong effort from both the UK and the EU at a time of considerable turbulence in the overall relationship.

There are five areas in which Brexit is likely to have an important impact on European security.

First, from 29 March 2019, the date on which the UK is due to exit, the EU will formulate its foreign policies without UK participation. The UK will no longer have a vote at the Political and Security Committee, or at the many other committees and working groups – both in Brussels and in diplomatic posts elsewhere – charged with developing and implementing common policies. There will be a strong mutual interest in developing new mechanisms for consultation and coordination, for example in relation to sanctions. But these are likely to be significantly weaker than those currently in place while the UK remains a member. Over time, the balance of internal policy debates within the EU will change, potentially contributing to growing divergence from the UK in policies and regulations. The removal of one of its most globally oriented powers also seems likely to increase the extent to which the EU focuses on its own neighbourhood. The UK, for its part, will want to ‘pursue an independent foreign policy’. It may struggle to balance competing demands on its limited resources from both European and global commitments.

Second, Brexit will have an immediate impact on the UK’s future defence relationship with the EU. The logic of Brexit points to a rapid disengagement of the UK from its role in Common Security and Defence Policy (CSDP) missions, including the relocation of EU’s anti-piracy headquarters at Northwood, the reassignment of the role of Deputy Supreme Allied Commander Europe (DSACEUR) – currently a UK general – in providing operational command of the EU force in Bosnia, the reallocation of the UK’s place on the roster for leading an EU Battlegroup in the second semester of 2019, and the relocation of the Galileo Security Monitoring Centre to one of the remaining 27 EU member states (the EU27). As one of the few EU states able to provide high-level military enablers, the UK has made a significant addition to the credibility of key missions. After Brexit, these arrangements may no longer be able to continue in their current form. If EU states want to maintain an option for involving the UK in future European military operations, work will be needed to create new structures for doing so. A potentially important step in this direction came with French President Emmanuel Macron’s proposal last September to create a European Intervention Initiative (EII), outside the framework of the EU, and the UK’s agreement to take part in it.

Third, Brexit will have an impact on efforts to maintain a strong European defence and security industry. If the UK leaves the Single Market and the Customs Union at the end of the transition period, it could have a significant effect on the cross-border supply chains of defence and security companies, especially if there is a divergence between regulatory structures (for example in relation to data protection and aircraft safety) and greater restriction on the movement of labour. While the UK will no longer be a member of the European Development Fund (EDF), it will be in the mutual interest of both sides to ensure that the Fund’s rule maintain maximum flexibility for involving UK industries in joint ventures with EU-based companies, and for joint EDF–UK funding of pan-European initiatives.

Fourth, Brexit could make it difficult to maintain current levels of cross-border cooperation in combating terrorism and organised crime once the transition period is over. Because of its unique character, based on the legal supremacy of EU law in defined areas, member states can maintain levels of police and judicial cooperation (for example, regarding arrest warrants and exchange of personal data) that do not exist with any non-member state. A new legal basis for the sharing of personal data between the UK, European agencies, and EU member states will therefore be needed. The prime minister has proposed a new security treaty to address these issues and has conceded that ‘when participating in EU agencies the UK will respect the remit of the European Court of Justice’, that the UK will need to maintain EU data protection standards, and that there will need to be ‘a strong and appropriate form of independent dispute resolution’. Yet the EU has already rejected British attempts to ‘cherry pick’ the economic sectors in which it will continue regulatory alignment, insisting that the UK must choose between full Single Market membership (the ‘Norway model’), involving full freedom of movement and commitment to follow all EU rules, and a looser Free Trade Area (the ‘Canada model’). For a security treaty to be possible in the absence of full UK membership in the Single Market, it will be necessary to separate it from this wider discussion. Whether this proves achievable may depend in part on whether the two sides can agree to align their regulations in those areas – most notably data protection – which play a vital role in both security and economic cooperation. Even if such a separation is agreed, the UK could be required to sign up to automatic adherence to future EU regulations, which will be agreed without its direct participation.

Fifth, this paper discusses possible security spillover from a failure to agree a close post-Brexit trading relationship. A disruptive Brexit could undermine the UK’s nascent recovery from recession and accelerate the relative economic decline of both the UK and some of its European neighbours. In doing so, it could further strengthen nationalist political forces across Europe, resurgent even in the EU’s most powerful states. It could also damage intra-Ireland trade, and make it harder to sustain the fragile political settlement within Northern Ireland.

The extent to which Brexit has serious strategic consequences for European security will depend on whether the UK and the EU can move beyond Brexit to create a new and substantial security partnership. This will not be easy, with political forces on both sides opposed to likely compromises. In the end, though, both the UK and the EU may come to recognise that they remain uniquely bound by common interests and values.

Malcolm Chalmers
Deputy Director-General

Professor Malcolm Chalmers is Deputy Director-General of RUSI and directs its growing portfolio of research into contemporary... read more

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