The US could do what Obama did in Western Africa and Lybia in the teens, and lead from the rear.
But I doubt that is how the Op Plans are written for a "REFORGER" style response.
As a practical matter, take a look at the 30,000+ already in Germany (permanently), the 10,000+ already in Italy (Permanently) and recent deployments
And more recently.
If conditions for Article V trigger
the US Forces are already there and seem unlikely to avoid being in the fight. Beyond that, the ability to phase in significant air assets (critical for any rapid response plan) is already in place in a variety of op plans.
I will remind you all that Mr Trump is not the president. You are taking counsel of your fears.
With all of that said,
Mr Biden's Pentagon team has announced that
the US Army is due to cut 24,000 from the force structure. (The news article I read suggested that this is tied to recruiting issues, but I am not sure what the truth is.
That sends a bit of a mixed message, as I see it.