What i think needs to happen is this, When the First boots land on Greenland, every American ambassador is called into every Nato Country, and given a note, that says you have 48 hours to remove your forces back to a peacetime level, or you will be required to leave every base on Nato soil, failure to do so, will see your forces surrounded and disarmed
in addition, The Nato countries should terminate Nato, and set up an European defence accord, along with other former Nato members, including Ukraine, Western European forces will then be free to aid Ukrainian forces on the ground to take back their country, and stabilise it,
The US will loose every european base, all arms contracts, lose all diplomatic advantages they have, possible travel bans, and limits on American travel beyond the US. the US economy would likily collapse, especially if countries started to shift debt they held.
It wouldn't surprise me if the plan is to effectively remove US troops from Europe, to aid Russia (although Russia will need some time to built up personnel and rebuild its arms). We could well fall into a trap if we decide to kick the USA out of Europe for doing the very thing intended to get us to take such action.
That said, I think that for now we should perhaps consider the USA as a threat and look at options to become more independent. As said above, the USA is in control of a lot of our equipment so the minute we tell the USA to go forth and multiply, we are at risk.
I mean, we're (UK at least) pretty weak anyway right now. The only comfort being that Russia is weak too.