Does it matter if it was sanctioned by UN? It was still an offensive action and not peace keeping one. I believe that Russia made a big mistake by invading Ukr

Does it matter if it was sanctioned by UN? It was still an offensive action and not peace keeping one. I believe that Russia made a big mistake by invading Ukraine but that doesn't mean they did not have something to fear from NATO. Maybe things would have been different today if NATO gave Russia a guarantee they will not accept Ukraine as a member. Maybe it wouldn't matter. We won't know for a long time but I think it would have been worth a try.