USA vs Canada, Mexico, NATO, etc
Wouldnt end well for us. Especially considering a significant amount of US citizens would also be against that war, so wed basically be fighting another civil war while also having to fight off other countries.
Then theres the whole Greenland and Panama Canal bullshit. USA would be stretched far too thin and fighting itself, itd be the easiest win ever.
https://i.imgtc.com/MGGa6Os.gif