I don't think it's likely, but I do think it's possible. If the US and EU get tired of helping Ukraine, they'll have a much harder time resisting Russian attacks. Once they do, why would Russia stop? Maybe they would. Maybe they'd pause, declare peace, and take the rest a year or three later. Maybe they'd just keep going. Putin saying he doesn't want it doesn't convince me in the slightest. He's a Soviet Union revanchist in terms of territory if not political system, and they owned the place before.

Not sure what the consequences of attacking NATO has to do with this.