This will be very brief. The long version is in the linked article. I’ll admit when I first heard this talk—actually, some time ago—I thought, No, this is too crazy. Never say never, I guess. There are, in fact, interest groups with an interest in escalation:

Will Biden Gamble on a Ukraine Coalition?
The Washington establishment is considering a risky and ill-defined intervention in Europe.
…
Today, the Biden White House appears to be considering the use of a multinational force aimed at Russia. The NATO alliance is unable to reach a unanimous decision to intervene militarily in support of Ukraine in its war with Russia. But as signaled recently by David Petraeus, the president and his generals are evaluating their own “coalition of the willing.” The coalition would allegedly consist of primarily, but not exclusively, Polish and Romanian forces, with the U.S. Army at its core, for employment in Ukraine.
…
I still have to say that this seems wildly impractical to me, from a strictly military standpoint. Neither Poland nor Romania have the military resources to do anything beyond committing a weird form of ritual suicide. I find it hard to believe that, short of nuclear war, the US could prevent such an outcome—and of course that would render everything moot, anyway.
I've been on night shift schedule and I wake up to this.
This article assumes facts not in evidence, namely that Poland/Romania/Whoever are among the "willing", as in willing to commit to a ground war with Russia.
My guess (Guess!) is that the Brandon regime is probably willing to do this, but no one else with the possible exception of the Brits. The Brandon people are plungers, but post Kabul and post a whole series of Biden's cognitive meltdowns they'll have God's own job finding anyone willing to commit to a venture like this under American leadership. The Poles/Romanians/other suckers would have to provide most of the ground troops and the US most of the air power. Our coalition partners would have to believe that A.) The Biden people know what they're doing B.) They won't see their power grid go down under Russian missile attack C.) Afterwards they won't glow in the dark. That strikes me as a tough sell. I don't think they'll find a lot of takers.
MacGregor isn't wrong to be concerned, but I suspect the Biden Administration is running out of willing coalition partners. It would take a rasher man that I to say this is impossible, but I don't think it's probable.
Maybe they'll wait a couple of months until they can emulate napoleon and Hitler with a nice winter offensive into Russia. Senile Zhou can surely do what they couldn't. Maybe he'll lead the charge. On a white charger. Him before any of my sons!