Or, if they decided to take lands belonging to allies.

Though after this administration I'm not sure we'll have any allies left.

If Trump’s term ends with NATO still intact I’ll be surprised.

If the US left NATO the remaining members would have even more incentive to stick together.

Ya, but not being intact doesn’t mean completely destroyed. I just don’t think the Europeans will ever trust the USA enough again to let them have a close relationship, even if Trump’s presidency ends with the US still a democracy.