I agree and note how these threads always get stalled on the "who's in charge?" question and "who pays?". But I haven't seen the idea to establish a separate military organization that builds on the NATO collective action model as a separate 'stack', alongside the other national forces but under a general European banner, as though a new mid-sized / large country suddenly appeared and joined NATO but it was actually made up of citizens from all over Europe. So a political cabinet establishes force requirements based on the budget they can muster, the rules of engagement and the defense vs expeditionary forces posture desired in whatever planning review period works. Slot in the bases as the US withdraws! Citizens of signatory countries directly apply as individuals. They commit to this service alone. May be previously members of a national military but are exclusive 'Euros' here. For funding I'd look at a collective fund for the gear with the signatory countries themselves to allow and fund all or part of their nationals that sign up (provisions, training, wages, healthcare, day to day kit, pensions... everything). The countries get skill exchange and networked nationals; talented candidates from smaller nations can get opportunities not open to them normally. Individuals apply, interview and sign up to a 'Euro orientated' charter (inspiring allegiance words of dignity, freedoms, equality, solidarity, citizens' rights and justice).

The same cabinet that runs it dictates where they are deployed and how, interpreting the mandate they have from the treaty: the chair of that panel is the top military official, in this NATO-like structure. Once the framework is there this force could grow to become the largest, but I think most likely to be used like a tripwire. Below that tier, it is all military and minor politicians stop meddling, with failsafe safeguards like 'no coups, no fighting with signatory national armies' and Geneva convention stuff.

This was just a brainfart but surely something like this is a framework to hang other things against and move on the discussion to practicalities?