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The Effects of Brexit on the Future of European Security Order and NATO: An Assessment

The Effects of Brexit on the Future of European Security Order and NATO: An Assessment

Cornelia-Adriana Baciu and John Doyle (Dublin City University)

 What helped the Spartan League to win the Peloponnesian Wars in the 5th century BC was the pursuance of a rightful and capable strategy. ‘Tactics without a strategy is the noise before defeat’ was one of the first lessons provided by the ancient Chinese philosopher Sun Tzu. While many have argued that ‘no strategy’ was Theresa May’s strategy on Brexit, the failure to anticipate the turmoil and impossibility of consensus in the House of Commons might prove to be fatal for the UK.

At the time of writing the probability of a withdrawal deal, postponement or a crash out without a deal is difficult to judge. What one can say for sure is that Brexit – the other intervening variable being Trump – had a ‘turning the tables’ effect on the collaborative potential in the security and defence domain in Europe. It triggered serious debates on European strategic autonomy and security capacity. New strategic instruments and frameworks such as PESCO, the European Defence Fund (EDF) and CARD, along with the advancement of the Military Planning and Conduct Capability to executive peace missions, could exponentially increase the value of defence cooperation and thus generate new assets in the EU’s crisis management capacity and international peace strategy. There is still some way to go until the EU would become a ‘force for peace’ and the planned 22-fold increase in the security and defence investment during the Multiannual Financial Framework 2021-2027 will be simply a first step to fill the vacuum left by the UK’s withdrawal.

In the scenario of a ‘no deal’, UK security and defence assets, including nuclear capabilities, will remain available to most EU member states via NATO. Thus, a move of the nuclear deterrent force under an EU umbrella, as discussed by some seems highly unlikely and would only be plausible in the case of a failure of US credibility to guarantee extended deterrence in the Euro-Atlantic community. In the scenario of a ‘no deal’, the UK would remain involved not only in NATO but in other initiatives such as the UK-led Joint Expeditionary Force (JEF) with the Nordic states or the European Intervention Initiative, and these would become more important for the UK to avoid complete isolation from emerging European security visions. However, it will certainly prove more difficult to advance cooperation outside of the trade-offs which are possible in a more broader institutionalisation framework attainable in the scenario of a ‘deal’. In terms of defence cooperation and collaborative defence procurement, the lack of an agreement between the EU and the UK would most likely exclude the UK from EU co-funding in frameworks such as EDF, which would constitute a serious disadvantage for UK-based firms. The Organisation for Joint Armament Cooperation (OCCAR), which is outside of the EU framework, could constitute an alternative channel for armament and procurement cooperation. OCCAR’s strategic role might, nevertheless, be weakened by the revival of the European security and defence policy and by the Brexit process, particularly in the case of a ‘no deal’. According to Art. 15.6 of the Administrative Arrangement between OCCAR and EDA, specific provisions of this collaboration could be reviewed in the case in which a non-EU Member State – which the UK will be after Brexit – becomes member of OCCAR.

While one might have expected a low British interest in the EU Common Security and Defence Policy (CSDP/CFSP), the UK expressed an explicit interest in its July 2018 White Paper on Future UK-EU Relations and on other occasions, towards remaining in a position of being able to contribute to, and shape CSDP missions post-Brexit. Notwithstanding this desire, however, being outside of the highly institutionalised setting of the EU, the format of cooperation between the UK and the EU will be altered and the UK will not be able to guide debates relating to possible future directions. The debates on the Galileo satellite system, for instance, have already shown that while the UK is willing to share access, the EU may less likely share governance and influence on such aspect with a third country. In a ‘no deal’ scenario, the possibility that the UK would remain an outsider to pivotal security initiatives would be strengthened.

In the scenario of a ‘deal’ between the EU and the UK, such an outcome would bring up the possibility for the UK to take part in CSDP on a bespoke or ad-hoc basis. According to UK domestic reports, the UK aims at a strategic-level agreement and a comprehensive framework for security cooperation, which, if materialised, could allow the country to maintain not only involvement but also a degree of influence on future debates on European security. Existing partnerships between the EU and third countries such as Serbia, Montenegro, Ukraine or Switzerland draw on Framework Participation Agreements (FPAs) and case-by-case input. They, nevertheless, do not foresee participation in decision-making structures of EU security and defence, such as the Political and Security Committee (PSC) or the Foreign Affairs Council (FAC). If the current withdrawal agreement is adopted, the UK will benefit from an informal role in the CSDP/CFSP during the transition period, as specified in the Political Declaration setting out the framework for the future relationship (Art. 92-104). This would offer the UK many avenues for consultation and cooperation. Some commentators have argued for a future ‘special relationship’ between the EU and the UK, involving a special UK ‘opt-in’ into CSDP/CFSP, including a seat in the FAC, when operations with UK involvement are discussed. This would imply that the UK would continue contributing to the EU security and defence budget (For a detailed discussion on the implications of a possible UK seat in the FAC, see Sven Biscop (2019), European Strategy in the 21st Century. New Future for Old Power, London and New York: Routledge). Yet, while most EU Member States would welcome continuing UK involvement in CSDP operations, UK participation in formal EU meetings seems very unlikely as it would be viewed cherry-picking and may constitute a precedent for other countries, including Turkey.

In conclusion, in a post-Brexit regime, the EU security and defence could become the institutional mechanism for integrating autonomous actors such as the UK and even the NATO transatlantic structure into a broader European security eco-system. Despite its weaker military capacity, the EU can offer coordinating mechanisms with diplomatic strategy, trade and development cooperation in which NATO has limited capabilities. It would also act as a counter-balance to the Trump administration’s limited engagement with NATO. Brexit will, however, inevitably weaken European security cooperation and the UK will, even with a deal, be an outsider to EU-led initiatives. The lack of awareness on these consequences may reflect the broader failure within the debates at stake in the UK/House of Commons to assess the impact of Brexit. Yet it has hampered contingency planning for both a deal and no-deal withdrawal.

This analysis is based on the forthcoming book Peace, Security and Defence Cooperation in Post-Brexit Europe: Risks and Opportunities, co-edited by the authors of this piece.


Professor John Doyle is Dean of the Faculty of Humanities and Social Sciences at Dublin City University and the founding Director of the Institute for International Conflict Resolution and Reconstruction (IICRR) in Ireland. His work on conflict resolution and the future of peace has been published among other places in the Journal of Common Market Studies, Ethnopolitics and International Peacekeeping.

Cornelia-Adriana Baciu is founding Director of the transnational Research Network ‘European Security and Strategy’ and a final year PhD Candidate in International Security at the School of Law and Government, Dublin City University. She specialised in European security, foreign policy and strategy, civil-military relations, regime complexity and research methods.