Seriously doubt any country on Earth is going to attack Russia and risk global thermonuclear annihilation over anything other than a direct attack on their own lands.
I think if Russia drops a nuke on Ukraine then even China will desert them.
India for sure will stop trading with Russia, lest it be seen to condone such insanity (India has a nuclear armed rival next door-India will not want Pakistan get any ideas).
I think this is the only reason Russia did not nuke Ukraine.
Seriously doubt any country on Earth is going to attack Russia and risk global thermonuclear annihilation over anything other than a direct attack on their own lands.