An interesting development in the past few days is that both sides have been testing how far they can take escalation. For example Russia has stated that arming

An interesting development in the past few days is that both sides have been testing how far they can take escalation. For example Russia has stated that arming the Ukrainians would be seen as an act of war, but numerous NATO countries have done so anyway and nothing more than strong words has followed. It is also widely accepted that NATO has been supplying the Ukrainians with satellite imagery and the like. OTOH, straight up delivering extra fighter jets or enforcing a no-fly zone is seen as "too much" at the moment. I think the West have several escalation steps more they can get away with if they are careful. After all, what is Russia going to do about it other than starting a nuclear exchange with NATO? The cost to NATO will be extremely high but Putin can be sure he won't survive either and that is what the whole thing was about from the start. It all looks very much like one of the "proxy wars" of the cold war era, only Russia forgot to do it by proxy this time.