Maybe I don't move in the right circles but I don't know of anybody who "wants anything back"!
You're a nice, educated guy - you move in different circles.
The EU army is definitely discussed as we speak!
It would be extremely difficult to create a working EU army. Only in Polish army we have German, Russian (and now American) tanks - different spare parts, ammunition, software - everything. To create a unified EU army would require a herculean work and, most of all, the concord of all the countries, which seems highly unlikely.
If PiS really wanted to buy tanks, it would make much more sense to get more Leopards (and even more to get gazillions of anti-tank weapons instead) which are already used by our army and beloved by our panzer troops.
Gefreiter Kania's army - the best fighting force ever! ;)