There is currently no ‘EU Army’. Member States voluntarily contribute to EU-led military operations. Brexit will affect how the UK contributes to these military operations. If the UK leaves the EU with a deal, future relations will be governed by a withdrawal agreement and any associated political declarations.

But what would a no-deal Brexit mean for the UK’s Armed Forces?

How does the UK currently contribute to EU military operations?

Although the EU does not have a standing force directly under its control, there are several EU-led military operations. Member States must agree on a unanimous basis to the creation of an EU-led military operation. Individual Member States then contribute capabilities and assets to that operation, on a voluntary and sovereign basis.

The UK currently contributes to seven out of 16 EU-led military operations. These operations involve approximately 200 British personnel and several military assets. The UK’s principal contribution to EU-led operations has been at the strategic command level.

Successive British Governments have stated that NATO is the cornerstone of European defence and security. This is supported by a network of strong multilateral and bilateral alliances and partnerships of which the UK is a participant. Government security and defence policy has also been shaped by permanent membership of the UN Security Council.

From the UK’s perspective, the EU has been a notable ‘soft power’ actor. The focus of EU efforts has been on crisis prevention, crisis management and post-conflict stabilisation.

In terms of military capability, the UK could also be considered a net contributor to the EU.

The strategic impact of a no-deal Brexit

At the strategic level, following Brexit the UK would no longer be involved in decision-making mechanisms for the Common Foreign and Security Policy (CFSP) and the Common Security and Defence Policy (CSDP). The CFSP and CSDP are used to co-ordinate joint responses to foreign policy challenges across all EU Member States.

There are also questions around intelligence sharing among the EU Member States. In the event of a no-deal Brexit there might not be a legal mechanism in place to share classified information between the EU and the UK.

Practical impacts of a no-deal Brexit

A no-deal Brexit would mean that the UK could no longer participate in, or assume command responsibility for, any CSDP missions or the EU battlegroups. All UK military and civilian personnel deployed on EU-led operations would have to return to the UK. All UK military and civilian staff seconded to the EU would also have to return to the UK.

The one exception to this statement is Operation Althea in Bosnia. Operation Althea is an EU led operation with access to NATO assets. As a result, UK personnel could continue to contribute to Operation Althea as a NATO Member State.

In terms of capability development, the UK would no longer be able to participate in the European Defence Agency (EDA). The UK would also be excluded from any projects currently underway under the pilot scheme for the European Defence Fund.

Ongoing defence cooperation

On the other hand, the UK’s ability to project military power would remain largely unaffected by a no-deal Brexit. ‘Hard power’ would continue to be the purview of NATO or ‘coalitions of the willing’. Any shortfalls in ‘soft power’ projection could be compensated for through other multilateral or bilateral frameworks.

Defence cooperation could continue through bilateral or multilateral arrangements such as the Anglo-French Lancaster House Treaties, the UK-led Joint Expeditionary Force, and President Macron’s European Intervention Initiative. Intelligence sharing would also continue bilaterally or through the Five Eyes network. As Sir Richard Dearlove, former Chief of the Secret Intelligence Service, noted in Prospect Magazine in March 2016: “Britain provides more intelligence to Europe than it gets back”.

The impact of no longer being able to participate in the EDA or the pilot stages of the European Defence Fund is also debatable. 90% of the UK’s defence industrial collaboration with other European countries is estimated to take place outside of the EU framework on either a bilateral or multilateral basis.

Post-Brexit involvement in EU operations

In the longer term, the UK could seek to re-negotiate its participation in EU military operations via a third-party framework agreement. The United States, Canada and Norway already have such agreements. The UK could also conclude a third-party Administrative Agreement with the EDA, and potentially the European Defence Fund, although third country access to that fund will be tightly controlled.

However, the political will of the EU27 to positively engage with the UK in such negotiations following a no-deal scenario is hard to predict.

There is also a school of thought which argues that, in defence terms at least, the EU needs the UK. According to this viewpoint the UK’s armed forces are a useful bargaining chip in any potential negotiations on a future relationship.

Given recent shifts in the international security environment, the increasing belligerence of Russia and a US President who appears to have very little time for European security or the US’s European allies, engaging the UK as a third country participant in CSDP, regardless of a no-deal scenario, may not be so unappealing.

Further Reading

About the author: Claire Mills is a Senior Library Clerk at the House of Commons Library.