That's what I noted early in the Ukraine crisis:
Of course, the biggest job will be to improve the logistics network of NATO to support the movement of western NATO forces into eastern NATO countries to come to the aid of NATO states under threat from Russia. That's the biggest brake on meeting a Russian threat.
Which is the basic reason why Putin's complaint that NATO has loomed over Holy Mother Russia was always a load of crap.
Not only didn't NATO move troops into the new NATO states until Russia invaded Ukraine, NATO didn't even create the logistics network to support pushing forces into eastern NATO.
We're out of practice moving troops to Europe, but we will learn.
UPDATE: Yes, Poland will become the new center of gravity for the United States Army.
The Army will need to hold the Suwalki Gap, conduct an offensive into Kaliningrad, reinforce Lithuania to hold the line there, and prepare for a counter-offensive into Latvia and Estonia to restore the NATO alliance's territorial integrity.
Which means we really need to get a move on the logistics issue.
UPDATE: With Poland as a center of gravity for our Army, it will help that Poland is serious about defense issues including reaching out to neighbors to the north, south, and east to bolster resistance to actual and potential Russian aggression.