About 20 years ago, a bit more maybe, the US was looking to reduce its footprint in a variety of areas beyond the massive movement of VIIth Corps out of Europe via the Mid East in 1990 - 1991.
Regardless of how much that footprint was to go down, the capacity to deploy if stuff gets hot again needed to be retained.
The ability to access bases both North and South of the Alps through which, and into which, move CONUS based forces was retained.
The concept of ops from JCS was "CONUS based/deployable" which has met with mixed success.
A variety of ops since 2000 have benefitted from the simple fact of 'there are bases there."
IMO, Exhorder has put his finger on it nicely.
The number of combat formations, particularly north of the alps, is waay down.
Basing rights and the capacity to train with allies in a comonly funded base has value for operations in area and out of area.
That the Poles are interested in a cushier security blanket may not matter to the Spanish, but it matters to the Poles.
Air ports of entry and sea points of entry, most of the latter in the NATO Southern Region, are a strategic capability that you can't make at home.
Remember what the real estate gurus talk about: location, location, location.
The arguments are, and remain, how much of the bill each member of this club pays.
As I noted, above, that's nothing new.
Retaining the relationships and the capacity to move "across the pond" is, so far, still a desired strategic capability.
But, the bigger pond on the other side of our nation is a pressing strategic priority.
And getting moreso by the week.