The UK and France must improve cooperation on defence and security to better deal with threats including Russian aggression, terrorism and cyber warfare, finds an expert taskforce led by former NATO Secretary-General Lord Robertson and former French Prime Minister Bernard Cazeneuve.

Research underpinning the taskforce’s final report was carried out by the Policy Institute at King’s College London and French think tank Institut Montaigne.

The taskforce concludes that while UK-France cooperation has never been so valuable, it has also never been so fragile. Brexit is one factor threatening the relationship, but it has long been under strain due to the failure of joint defence industrial projects such as the Future Combat Air System and attempts to develop the next generation of nuclear submarines.

A stronger defence and security relationship between the two countries is especially vital in light of a more isolationist and unilateralist United States under President Trump, the taskforce says. This has shifted focus towards the Pacific region and away from Europe, and more fundamentally, means the United States has a weaker commitment to the tenets of the existing liberal world order.

This underscores the need for European countries – and the UK and France in particular as Europe’s biggest military powers – to be more self-reliant when it comes to defence and security, the taskforce argues.

The taskforce recommends that the UK and France should:

• Ensure that Brexit does not endanger security cooperation between the UK and the EU27. Security issues need to be isolated and insulated in the negotiations for the UK’s withdrawal from the EU, and kept separate from the trade and customs aspects of the talks.

• Develop a joint doctrine for responding to cyber threats. Both the UK and France have been targeted by cyber attacks in recent months. The strategic dialogue on cyber threats that was established at the Sandhurst summit earlier this year was a good start, but does not go far enough in combatting them.

• Formalise intelligence sharing between the two countries. At present, such cooperation works largely on an informal basis, and is built on trust and personal relationships between members of the intelligence services. But this is not as efficient as it could be: more structured links are crucial when it comes to counter-terrorism and joint police operations.

• Save money by having both British and French armed forces share training facilities and cooperate on maintaining equipment. This would release funding for other areas of defence spending.

Read the taskforce's report, The UK-France defence and security relationship: How to improve cooperation (pdf) (traduction française)

Find out more about the project, including the full membership of the taskforce.