EU launches new era in defence co-operation
European Union countries have launched a programme of joint military investment and project development aimed at helping the EU confront its security challenges.
Twenty-three of the EU's 28 member nations signed up to the process, known as permanent structured co-operation, or Pesco.
Britain, which is leaving the EU in 2019, and Denmark with a defence opt-out were among those not taking part.
EU foreign policy chief Federica Mogherini described it as a "historic moment in European defence", and added that "23 member states engaging both on capabilities and on operational steps is something big".
Those who did not sign up can join later.
Ms Mogherini said countries have already submitted more than 50 joint projects in the fields of defence capabilities and military operations.
Britain can take part in some if they are of benefit to the entire EU.
Ms Mogherini said Pesco, backed by the EU defence fund, "will enable member states to use the economy of scale of Europe and in this manner to fulfil the gap of output that we have".
Their signatures are a sign of political will but the programme will only enter force once it has been legally endorsed, probably in December.
German Foreign Minister Sigmar Gabriel lauded the agreement as "a great step towards self-sufficiency and strengthening the European Union's security and defence policy - really a milestone in European development".
Under the co-operation, member countries will submit an action plan outlining their defence aims.
Ms Mogherini, EU military chiefs and the European Defence Agency will then evaluate whether the plans are being respected.
Those not living up to their commitments could be kicked out of the group.
EU officials insist this is not just bureaucratic co-operation, but real investment that will help develop Europe's defence industry and spur research and development in military capabilities that the bloc needs most.
Ms Mogherini said the move would complement Nato's security aims.
The EU, she said, has tools to fight hybrid warfare - the use of conventional weapons mixed with things such as propaganda and cyber-attacks - that the military alliance does not have at its disposal.
The EU can also bring its political and financial weight to bear on security challenges, such as the use of development aid in Africa, where Nato has no real foothold.
Under Pesco, EU countries will commit to increase military spending, but not to specifically adhere to Nato's bottom line of moving towards 2% of gross domestic product for defence budgets by 2020.
By working together on joint projects, nations will be able to use their combined spending weight to purchase much-needed capabilities like air transport or drones.
"The real problem is not how much we spend, it is the fact that we spend in a fragmented manner," Ms Mogherini said.
Mr Gabriel said working together is "more economical than if everyone does the same. I think that European co-operation on defence questions will rather contribute to saving money - we have about 50% of the United States' defence spending in Europe, but only 15% of the efficiency."