How will defence and security be affected by Brexit?

Defence and security were not critical issues to those who voted for the UK to leave the European Union. Since the referendum, these topics have remained in the background, with trade and migration issues still dominating Brexit discussions. Nonetheless, the decision to leave the EU creates fresh challenges for UK and European security—deepening uncertainty at a time when little certainty exists.

Policymakers face the complicated task of untangling the UK from EU institutions, all while grappling with the resurgence of Russia, the Mediterranean migrant crisis and terrorism at home and abroad. Given these other challenges and the enduring common interest—even interdependence—of the UK and EU in defence and security matters, such issues warrant continued co-operation after Brexit.

RAND Europe’s recent report, Defence and Security after Brexit, outlines the range, scale and complexity of the issues that must be addressed. These include the potential impact on the defence capabilities of the UK, EU and Nato; the domestic implications, especially for Scotland and Northern Ireland; the resulting uncertainty about defence spending, industry, R&D and innovation; and new challenges for co-operation on transnational issues such as counterterrorism, space and cyber security.

The months since the referendum have already seen a flurry of developments. The EU has reinvigorated proposals for an operational headquarters for European training missions and a new €500m annual fund for defence research. The UK has renewed, for now at least, its membership in Europol, a crucial EU security body headed by a British official (40 per cent of its caseload involves the UK). The National Audit Office has warned that the UK Ministry of Defence faces a £6bn hole in its spending plans—on top of the £21bn of upcoming military spending that must be paid for with a weakened pound.

These are only some of the more obvious implications and uncertainties. There are a myriad of other important technical issues that will have to be resolved during and after Brexit negotiations.

Considering these many esoteric issues will no doubt cause Brexit negotiators many a sleepless night. How will border controls work in Northern Ireland, Gibraltar and Calais? Should the UK retain the Deputy Supreme Allied Commander Europe role in Nato (given he or she theoretically commands EU operations, too)? What is the future for existing co-operation on defence and security between the UK and France, or the British-led Joint Expeditionary Force?

Faced with the sheer weight and complexity of issues to be addressed, there is a temptation for the UK and EU to focus narrowly on short-term fixes to each of these uncertainties. Certainly, co-operation mechanisms can be renegotiated, reworked and finessed. In Whitehall and Brussels, however, the scale of this task will strain finite organisational and intellectual capacity for proactive, long-term strategy-making. Meanwhile, three key questions risk being overlooked.

First, what sort of actors do the UK and EU want to be on the geopolitical stage, after Brexit? The referendum debate focused on the merits of leaving or remaining in the EU. Now that decision is made, what sort of role does the UK aspire to in the world? What is the future level of defence ambition for the EU and its new global strategy?

In the language of military strategy-making, there has been much discussion of how Brexit will impact “ways” (the methods and tactics) and “means” (the tools and resources). Less clear is how the “ends” (the desired outcomes that the UK and EU seek to achieve in terms of defence and security) will change, both throughout the Brexit negotiations and once the divorce is finalised. This will depend on what kind of role both wish to play in a post-Brexit world, a question that appears to have received little attention so far.

Second, how can voters of all generations be better involved in this grand strategic debate? The Brexit referendum exposed a deep divide between policymakers and the populaces they represent; a divide similarly witnessed in Donald Trump’s surprise victory in the United States, the outcome of the Italian constitutional referendum, and the rise of populist parties across Europe.

As the UK and EU move to define new defence and security roles, these can only be truly sustainable if built on inclusive national conversations. Security initiatives or defence integration must demonstrate relevance to voters’ everyday values, fears and aspirations.

Finally, how can both sides minimise the risk that defence and security topics get left behind in negotiations, especially if tensions flare over issues such as trade and migration? There is a perception that the UK is a net contributor to European defence and security—that it gives more than it gets back. There is a temptation, then, to see this as a bargaining chip with which to extract a more favourable deal on tariffs or the UK’s “exit bill.”

Playing this card is a high-risk strategy, which is likely to threaten the security of both sides. For one, the UK’s perception of the value of its hand is just that, a perception. Not all EU members will care about the UK’s defence contributions as much as about trade or European solidarity.

Worse, given the enduring mutual interdependence in this area, if the UK or EU take a “zero sum” approach to defence and security, both face a lose-lose situation. The only winner from a messy divorce would be those who seek to benefit from a weakened and more divided western alliance on the world stage.