Why this waffling around helping a western democracy defend itself against an enemy that purposefully bombs children's hospitals, is run by a dictatorship, and

Why this waffling around helping a western democracy defend itself against an enemy that purposefully bombs children's hospitals, is run by a dictatorship, and spews active measures disinformation campaigns all around the world? Let me remind you that World War 2 effectively happened from the western democracies repeatedly appeasing the dictator's territorial ambitions and doing absolutely nothing to defend countries like Czechoslovakia and Poland, not from "sleepwalking into war"