The US and NATO are looking I think for any reason to truly enter the fight at this point. They keep positioning troops, weapons, ships near the area in shows of strength. I think when the moment comes that they see the ability to swiftly take Russia out of this war and do major long term damage they'll move quickly and decisively. Or the minute Putin does something like start a nuclear problem with the power plant becomes the minute that NATO finally sees the red line as crossed and moves in decisively and quickly.
Russia should think long and hard about that, because once they make that move, I don't think they'll stop with just pushing Russia out of Ukraine, I think it becomes a process to topple Russia completely, remove all access to nuclear weapons, and install a new government.