The Just War of the Ukrainians – WSJ

Russia s invasion of Ukraine is illegal under international law, and it is unjust according to every version of just war theory. The decision to begin a war and the subsequent conduct of the war have always been subject to moral judgment. In Europe, just war theory dates from the Middle Ages. It was most fully developed by Catholic theologians, but it also appears in Jewish and Muslim versions. (There are Hindu, Buddhist and Confucian versions, too). And for just as long, realists have denied the meaningfulness and the efficacy of all such judgments. Realism is the major alternative to both international law and just war theory.

via www.wsj.com

Michael Walzer — a leading political philosopher and exponent of just war theory. A characteristically fine, brief essay.