I wondered the same at the time. But I'm no longer sure it would have made a difference, Putin might have invaded anyway. There are those who have argued that for years. With the amount of destruction and killing I no longer feel Russia has a leg to stand on about geographic security. I also believe NATO wasn't going to survive. If he really cared about Russian security he would have claimed a fake victory after a week and gone home. Then he could retool. Instead, it seems personal, madness. Anyway, thanks for comment!