The move has been spurred by US Donald Trump’s accusations that EU states don’t pay enough into NATO.
The other motivation is that it could diminish the union’s dependence on US military support.
EU foreign policy chief Federica Mogherini, called the pact ‘historic’ as ‘the real problem is not how much we spend, it is the fact we spend in a fragmented manner.’
The UK had always resisted the idea of joint EU defense, fearing some kind of big ‘European army,’ but the country’s planned exit from the bloc has removed that hurdle, allowing 23 other EU countries to move forward.
The UK could still be involved post-Brexit but it will come with a price tag.
The group will have a €5 billion European Defense Fund to buy weapons, a different fund for operations, and also get money from the EU budget for research.
The EU will have stronger, better synchronized national military forces to respond to crises together.
German Foreign Minister Sigmar Gabriel called it a ‘milestone in European development.’
EU leaders will sign the legally binding agreement in December.