There will never be an invasion of the US by its enemies as long as the US has nukes, so that one is ruled out.

When and if the US starts lobbing nukes (entirely possible) the reasoning behind that becomes a whole lot less, particularly for what humanity is left after the pyrrhic victory over YanKKKeestan. And if and when the US balkanizes or enters civil war- if it doesn't wind up nuking its own citizens in the process (also entirely possible) the entire world should see to it that the dreaded settler-imperialist, hegemonic ideology is rooted out in its entirety and support whatever factions might allow that.

Honestly I don't think there can ever be anything even remotely considered peace, unless the entirety of the US and the Anglosphere is de-Nazified (or rather, de-settlerized- not depopulated of whites, but having the entire ideology and even the mentality dealt with akin to the cultural revolution on steroids). Personally I live in an Anglo country as well and that's certainly my take on it, these are the countries that for the past 200~ years have been promoting every evil imaginable all across the globe (not talking about progressive things, those are the rare showings of humanity albeit often repurposed for PR instead), that have been waging war and genocide against indigeneity across the entire globe (taking up the leadership mantle of 500 years of western genocide and barbarism).

American and west European culture will have to be rebuilt and re-examined from the ground up, as the Soviets did (and with the assistance and oversight of the entire world upon the west, there should be no leeway). And American and west European state frameworks and institutions will also have to be rebuilt from the ground up, the rot is simply that deep.

This all sounds simultaneously fatalistic and idealistic- but my expectation is that the Yanks and the imperialist mentality will truly push things to their furthest point before there is any hope of changing course, that the spiral will only further continue, and for who knows how much longer, before finally they reach a breaking point. I hope not, but seeing the sheer pervasiveness and control of the neocons, of neoliberalism, and knowing firsthand how the culture of settlerism is, this is what I'd expect. And when things do reach that point (and if we all still live after, or not) whatever remains of humanity will have to ensure the settler-imperialist world system never develops again.

I'd genuinely like to be proven wrong, to see even the US/collective west with all their flaws disband NATO, ideally even start negotiating with or seek to join BRICS, and accept the end of empire with grace and get to work on resolving their own internal issues through peaceful reform if possible. Of course, we all know just how ridiculous, unprecedented, and structurally impossible any of this would be.