What war in history would you least want to fight in?

World War I, western front. Both sides were heavily entrenched, with machine guns guarding those trenches. The tactic was to charge straight into machine gun fire, basically suicide missions.

The war I would least want to fight in would be the Vietnam War, from 1954-1975. The reason being that any nation that insists on drawing a line of demarcation (like the U.S. did in 1954 with "north Vietnam" and "south Vietnam") between the thinking man and the fighting man is liable to find its fighting done by fools and its thinking done by cowards. I will give you a hint, the U.S military were the former, and the U.S. politicians who sold the war to the American public were the latter.

I wouldn't want to fight in any war, but if I had to choose, it would be World War I. Trench warfare, chemical and biological warfare, line charges, etc.

The ones where people fought over nothing, like in Iraq and Afghanistan and Vietnam.

Fighting the Japanese in WWII was fine, they attached us, and the Nazi's, well, fighting Nazi's is a thing you can be proud of, but killing a bunch of Iraq's, in their own country, so that a few rich people can get even richer in oil, is just murder, that is not war.

American's have forgotten that going into France, and helping the French people, fight Nazi's, who have invaded them, and help them get the Nazi's out of their country, is not the same thing as invading Iraq, and killing everyone who is not white that lives there -for money, for the rich.

The Western Front in the British, French or German Armies. It was brutal even for the American Army and Marine Corps which were in the heavy fighting for less than a year.

the next one - all of the wars from history are over

WW1.

A senseless war full of senseless slaughter of the ordinary soldiers on all sides.

The American Civil War - when the possibility existed that I would have to kill my brother, father, uncle, cousin if they were Union soldier(s) and I was a Confederate soldier.

The circumstances as to the politics were all different. To have the reality of all is impossible. For that reason I have no answer.