The impact of Brexit on the Common Security and Defence Policy of the European Union


by Ana Torres Rego, Master's degree in EU Law of UMinho

The winning of the campaign “Vote Leave”, in the referendum of 23 June 2016 held with the view to expiry the United Kingdom’s accession Treaty, turned out to be one of the biggest challenges facing the modern history of the European Union.

For its turn, if on the occasion when Article 50 of the Treaty on European Union was invoked in 2016 the earlier speeches of the Britain Prime Minister Theresa May can be summarised as “Brexit means Brexit” – as an answer against free movement of people; in the recent past, the increased awareness of the high cost for all parties involved of a hard Brexit has opened space for dialogue and negotiation.

The change of direction noted from October 2016 to March 2017 is very clear in the formal communication[i] notifying the United Kingdom’s intention to leave the European Union sent by Mrs. May to the European Council. That letter, where concerns related with the state of defence of the EU from security threats are strongly expressed, suggests first and foremost the British willingness to keep a special relation with the European Union in defence and security matters in order to ensure the status of security power for both among the potencies in the international order.

However, the United Kingdom’s priorities along the process had been established under the idea of a hard Brexit, i.e., all the process has been guided by so strict independency purposes to allow an exit from the European integration project without an agreement. In fact, British people voted for a future relation focused on the European Single Market, customs union and a special agreement about fair trade and the fight against terrorism and international crime, as well as cooperation in the security and defence.

In particular, with regard to the Common Security and Defence Policy, as the UK being a significant nuclear power, Brexit can lead to the loss of military and diplomatic capabilities, in addition to the loss of intelligence and knowledge on this specific area. This policy is designed to provide the EU with the capacity for autonomous action when responding to international crises, without prejudice actions taken by NATO.

The defence industry is a major industrial sector based on research and innovation, and centered on engineering and cutting-edge technology. The sector has an important spin-off effect in other sectors such as electronics, space, and civil aviation. It is a key sector for Europe’s ongoing development as a world leader in manufacturing and innovation and to improve European’s economic competitiveness among economic blocs as United States or Russia. The European Commission is actively promoting the competitiveness of the European defence industry.

The objective of defence industrial policy is to develop a competitive and innovative European Defence Technological and Industrial Base, which has a significant importance for an effective EU Common Security and Defence Policy.

The defence sector enterprises, which are extremely important to the supply chain, are mostly concentrated in six EU countries, namely, France, Germany, Italy, Spain, Sweden, and the United Kingdom.

Accordingly, with the exit of UK from the European family, the measures and goals from the last few years towards a European Defence Equipment Market may also have to be redefined.

Although, despite all the mentioned capabilities and the important role played in the establishment of the European Defence Agency, as security and defence are the heart of the British self-view of its national sovereignty, this country has always had a kind of a distinctive status inside the European Union – actually, the UK has never been really committed with the implementation of this common policy. Due to the military capabilities halted, and because of the historical relations with the United States in these matters, the European common policy in the global relations – for instance, within the transatlantic relationship’s framework – hold the UK as one of the most important countries, if not the most relevant one, in the European defence paradigm.

That’s why, beyond the obvious loss that can be felt in the defence industry, considering the UK is the strongest member state in the security and defence market, we believe Brexit can actually leads to a deep development of the terms of the European military capabilities, but also increase cooperation based on bilateral agreements between member states.

In this regard, inside the European Union, France was UK’s best ally in this domain. We can mention Saint Malo joint declaration of 1998, or even the Lancaster House Treaty signed in 2010. Towards this reality, as Brexit negotiations go on, it has been interesting to notice a changing of position of Germany and France in the game of the common policies about European security and defence. These countries, that signed themselves a joint statement in 2016 to empower the European defence, are now also demonstrating the will of truly enhance the integration of security and defence in the frame of the integration project as never shown before.

Despite the non-approval of Brexit agreement yet, UK’s and European Union’s leaders already confirmed the maintenance of cooperation in defence, which are expected to happen under the Permanent Structured Cooperation mechanism provided by the Lisbon Treaty. This cooperation can be particularly important in international missions where NATO takes the decision to not take action. In the light of this picture and still without any agreement at sight, it seems Brexit can lead to much more uncertainty in the future concerning security and European external policies, strongly impacting in military and defence domains.

[i] Article 50 notification letter from the United Kingdom in

Picture credits: HMS Belfast…  by Barry Marsh.

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