No matter who is President, half the country will be rooting for the other side.
Any "hot" war with a major power will also bring with it civil conflicts at home as various factions use the pandemonium to settle scores.
It won't be like WWII with an entire nation united behind a just cause. It'll be street fighting between left and right elements fighting each other and amongst themselves.
We have no idea of the chaos.
You’re exactly right.
We are a divided country, and one side will do anything, regardless of consequence, to gain advantage over the other side.
And what makes it so much worse is that the side I’m speaking of are actual American Nazis, and they’re going to have to be dealt with in similar fashion as the previous Nazis.