Nine European Union member states agreed on Monday, June 25 to form a joint military intervention force designed to rapidly deploy around the world. The European Intervention Initiative, proposed last year by French President Emmanuel Macron, has the support of the United Kingdom as it prepares to leave the E.U. next year.

Foreign ministers from Belgium, Denmark, Estonia, France, Germany, the Netherlands, Portugal, Spain and the U.K. signed a letter of intent in Luxembourg to form the rapid intervention force.

25 juin 2018 : l'initiative européenne d'intervention voit le jour à Luxembourg. pic.twitter.com/0YDcDSEOIa — Florence Parly (@florence_parly) June 25, 2018

Macron announced the planned force in a speech at the Sorbonne last September, and October’s Strategic Review of Defense and National Security makes plain that the European Intervention Initiative is high on France’s agenda.

European intervention force

During Monday’s meeting the Council of the European Union adopted governance rules for projects within the framework of Permanent Structured Cooperation on security and defense, or PESCO.

Twenty-five E.U. members signed PESCO agreement in December, but it’s unclear whether the U.K. will be able to participate after leaving the bloc.

The sequencing of the more binding PESCO commitments is expected to be defined next month, with a list of projects and participants due in November, when the council will also decide on conditions for participations of third states, such as the U.K. or the United States.

The U.K. has traditionally opposed anything resembling a ‘European army’ but is eager to support smaller initiatives outside the scope of the E.U.

In May, U.K. junior defense minister Frederick Curzon said that London was “very keen to support” plans for a military force that could be deployed rapidly to deal with crises.

French Defense Minister Florence Parly told Le Figaro on Sunday that the European Intervention Initiative is “clearly an initiative that allows some non-E.U. states to associate. The U.K. has been very good because it wants to maintain cooperation with Europe beyond bilateral ties.”

The U.S. and NATO have also expressed concerns about PESCO, with U.S. Defense Secretary James Mattis apparently worrying about it “pulling resources or capabilities away from NATO.”

NATO Secretary-General Jens Stoltenberg has said that such European defense efforts “can make a contribution to a fairer burden-sharing between Europe and North America,” but that E.U. efforts to boost defense spending under PESCO were only welcome if they are coordinated with NATO plans.

Stoltenberg was in Luxembourg on Monday for talks on NATO-E.U. cooperation ahead of the NATO meeting in Brussels next month.

“We need to be able to move forces quickly throughout Europe, when needed,” he said after meetings.