NATO was always a tool for the Americans to play world war games and protect their own interests.
East Europe never forgot Potsdam and the Iron Curtain. There's no 100% guarantee the US would honour an Article 5 invocation by some East European member, if the Russians attacked, and with Trump at the helm, the uncertainty is growing.
I'd like to see where else could the US take those bases and soldiers and equipment and use them in the ME as they have til now. And if they do take them to Poland, I wish Poland all the luck. Though I wonder if the Russians will let Trump do so - if it were me in control, and my projected enemies moved weapons to my border, I'd do anything possible to stop them. It's just logical.