I'm not changing any story. If you go back to the start of the discussion then you'll see that it's the same thing I keep trying to explain to you over and over throughout this thread. Meanwhile, you just keep making straw man arguments instead of engaging with what I'm saying.
The realistic way to read this is that Russia could retaliate using nuclear weapons in Ukraine, and then the ball will be in NATO court where NATO has to decide if they want to escalate further towards a nuclear holocaust or back off. Both sides can play the escalation game.
Of course, Russia could also escalate asymmetrically, for example they could provide weapons to Yemen, Syria, and Iran that could shoot down stuff like F35s and get past AD. The US is incredibly exposed globally, and there are plenty of pressure points that Russia can exploit. This is the main reason I don't expect Russia to respond directly to strikes into its territory.
The US has ruined and degraded Syria, neutralized its regional power, and turned it into a destabilized interzone.
Yet, Syria is still a viable state and the US forces in the region are slowly being squeezed out. The point here was that the objective of getting a regime change in Syria failed. Again, if US couldn't even take down Syria, there was no hope of this working in Russia.
Meanwhile, you don't seem to understand the importance of Russia to China. Russia provides a shield in the west that prevents China being surrounded by NATO, and it provides China with the natural resources China needs meaning that it cannot be blockaded. These two factors make it vital to China that Russia stays stable and friendly to China. Which means there was absolutely no scenario where China could allow Russia to be defeated.
Ukraine can claim whatever it likes, they're just a proxy. However, if Russia started lobbing Iskanders into Texas from Mexico then we'd be instantly in WW3 scenario.