Poland had major involvement in Iraq and Afghanistan, although they could have said “fuck you, take care of your shit yourself, America.”
This is the kind of thing that allies do for each other, the reason why NATO exists.
Also, Poland is currently bulding three new brigades that will be stationed and in 24/7 operational awareness as of the end of the year on its eastern border. Interestingly, google news only spits Russian propaganda page news article about it:
Last but not least Poland has currently one of the strongest armies in Europe, way ahead of Germany, for example.
So they are doing their bit, they just need other boots on the ground so that war becomes impossible, not only impractical for the Ruskies.
EU is based on international treaties to which all countries signed up to. Among the basics are 4 EU freedoms - free movement of people, goods, services and money.
If UK doesn’t like what it has on its own signed up to, it has two options. Annul them or renegotiate them. If they want to renegotiate them, they must gain support of counterparties.
If UK doesn’t like free movement of people, it should not have signed up to it in the first place.
Most wars were fought among European nations, not external threat.
The problem is that now when internal threats seem to be non-existent, most EU countries forgot that external threats might emerge, a.k.a. Putin.
That was the case only when buying from licensed stores, not during private purchases.