So it would be better to let a fascist Russian dictator crush Ukraine, maybe for all time, and inflict who knows what horrors on them? Doesn't sound better than what is happening now. Looking the other way would likely have lots of unforeseen consequences. It would embolden any leader with aggressive goals and that in turn would start an arms race for any country that might feel threatened by a superpower or regional power, including obtaining nuclear weapons. Defense contractors win either way.