I doubt they'd adopt outright appeasement, but they would be walking very cautiously.
I do not know what kind of mental gymnastics you make when you say NATO doesn't support the war in Ukraine, but it actually does - with the NATO SG going to Ukraine in a show of support.
AFAIK, there is no precedent to what will happen if a NATO country attacks another NATO country - we came close to that when the Turks and the Greeks almost started fighting a few years back.
The British Armed Forces swear an oath of allegiance to the King not the British government.
If he says go, they go.
It would be a gamble for even Trump that Britain can't launch nukes to defend a Commonwealth ally (obviously that would probably be the end of the UK but we've faced that before, eh).
This conversation is so stupid though.
As I initially asked: would you be willing to end your own country just because you feel like you need to defend another country on another continent against an adversary you have no chance of beating?
In this hypothetical situation the opinions that matter are those of the men in the subs that have just seen their family and friends wiped out.
They've got roughly 120 active warheads to play with and realistically no one is going to stop them all.
So if you add up the damage from that plus the loss of a major trading partner and military ally it kind of seems unlikely to be a profitable venture for anyone involved.
I think it would be a bigger loss for the UK to do something stupid than for the US do to something stupid.
I guess we have to see how it plays out with Greenland - most likely scenario would be he'd go after Greenland first if it ever comes to that.
But it’s all academic anyways. The US military would eagerly lead a coup before willingly attacking the UK or Canada, particularly if non-conventional means are threatened.
Consider that nearly every officer has done several war games or exercises alongside UK or Canadian officers. This is true both of NCOs and senior leadership. Being friendly with their armed forces is institutional. It would be easier to convince the Marines to attack the Army than to convince them to attack their Canadian counterparts.
That doesn’t go away quickly without good reason even with new orders.
An attack on a Anglophone Five Eyes NATO member is militarily close to a civil war and could rapidly lead to a civil war.