Ukraine has never been a threat to Russia like Iraq was to the ME. We didn't annex territory and keep it for ourselves, oh wait, I mean land troops in plain clothes and force the population to "vote" for annexation. And when all was said and done, we left Iraq to the Iraqis, it's clear that Putin doesn't care what Ukrainians want. Bottom line, we went into Iraq to liberate it, Russia went into Ukraine to conquer.
As far as NATO, do you really think the population of Europe would support a new war against Russia? Besides, we've learned the value of paper when Russia interfered in Ukraine's affair, which they agreed not to.