War is ugly. There is no such thing as a good or clean war. There are, however, just causes to fight for on occasion.
Nobody hates war more than the soldier who has fought in one:
"I doubt whether any of these [pacifists], with their academic or dogmatic hatred of war, detest it as much as I do. [The pacifists] probably have not seen bodies rotting on the ground and smelled the stench of decaying human flesh. They have not visited a field hospital crowded with the desperately wounded. What separates me from the other pacifists is that I hate the Nazis more than I hate war. My hatred of war will never equal my conviction that it is the duty of every one of us . . . to carry out the orders of our government when a war emergency arises."
-- General Dwight David Eisenhower, 1943