It’s not too late for the US/NATO to assure Russia that we will go no further on breaking promises made in writing and verbally by sitting US president(s) regarding NATO expansion east. We can guarantee that NATO won’t expand further and that Ukraine won’t be a part of it. We can guarantee the removal of all US-backed sanctions. All of that, of course on the condition that Russia remove all troops and personnel from Ukraine. We could even throw in the removal at least some of our personnel and weaponry that’s draped around significant portions of the Euro-Russian border.
We’re the big dog. Not Putin and not Russia. We’re the powerful ones. It shows that strength to make concessions to avoid further loss of life, famine and a possible Nuclear conflict.