Signing the security pact on Monday is just a step in the process.
France wants to severely restrict non-EU companies bidding for the bloc’s defence contracts, including the UK but Canadian and American firms too.
If the EU is spending its taxpayers’ money on defence, it argues it should be spent with EU companies to help boost EU economies.
Paris also says, in this rapidly changing world of shifting alliances and allegiances, the EU should be self-reliant, not dependent on suppliers outside the bloc.
Sceptics suspect France, which has a sophisticated defence industry, of wanting to hoover up lucrative EU contracts for itself.
But it looks like it is losing the internal EU argument, with the Nordics, the Baltics, Poland, Italy and the Netherlands favouring more openness on defence contracts, and particularly with the EU’s biggest economic power, Germany, championing the UK.
“Germany and France have very different attitudes towards the UK,” says German economist Armin Steinbach from think tank Bruegel.
Germany will always put relations with EU heavyweights France and Poland first, says Mr Steinbach.
But he believes the UK will be helped in defence and economic negotiations with the EU by new German Chancellor Friedrich Merz, who argues “a unified Europe is the absolute priority in the current geopolitical setting”.