re: "War may sometimes be a necessary evil....
That's a good indication why Carter was a failure as an American President.
Some wiser quotes:
“He who passively accepts evil is as much involved in it as he who helps to perpetrate it. He who accepts evil without protesting against it is really cooperating with it.”
Martin Luther King, Jr
The world is a dangerous place to live, not because of the people who are evil, but because of the people who don't do anything about it.
Albert Einstein