The US and Nato have been trying to force Russia in to a corner for decades, and this may be the beginning of that result. I'm not justifying the invasion, but I can see how Russia views Ukraines membership in Nato as a huge secruity issue. The US would never allow Russia to keep armies in countries surrounding it. The US has steadily been pushing for war with Russia for a very long time. Biden had no real plan to deal with this, and he was outplayed by Putin. Biden had mentioned something about being ready in the future, but unless that means boots on the ground in Ukraine, or planes in the sky, then the US and Nato aren't doing shit. I don't believe the US has support for joining this war, and if they were to do a poll I'm positive that they citizens of the US would largely be antiwar in this case. I don't really know what Nato intends to do here, but I'm going to assume nothing unless it's outside of Ukraine. I also think the US is going to need Russia's help in the coming war with China that I believe is probably going to happen.
Sanctions, negotiations, hostile relationships, but I don't see it going further once Russia takes what they want. Hopefully they don't try to drag Nato in to this.
I also have to say it even though you guys will call me a conspiracy theorist, but the US has an incentive here to plan a false flag attack in Ukraine and blame it on Russia. Some tragic event that harms citizens, to try and garner support for the US or Nato to get involved. If you think that could never happen, I don't think that's the case.