Putin knows he can’t be kicked out of Ukraine until NATO commits to total air dominance. Such a program would be very costly for NATO in terms of pilots, planes and political capitol. The Russian air defenses are not pushovers, the Russians have the planes to make a fight in the air, and the Russians would be able to resupply at least in the early stages, before total dominance is achieved, if it ever is.
The Russian response to NATO entering the air war would probably be more surprising yet logical than I can imagine. I’m sure whatever it is would be quite costly to the West in some manner or another.
May it never come to open war for the sake of our men and women who serve.
But if it does, strikes will be outside Russia also - including our aircraft carriers.
One might do well investing in a ferry service where the Golden Gate Bridge currently exists.