Radar, infrared tracking sats, trigonometry, and the quadratic equation are how other nations besides Russia will know the nukes aren't for them.
Also, we have nuke gravity bombs and cruise missiles; removing Moscow doesn't require cracking open the silo's in the midwest or telling our boomers to go loud, just some air strikes with tactical nukes or tac nukes delivered by cruise missile.
Neither of which is likely to cause the CCP to mistake it for an attack on them, and is we make it very open that so long as no Russian nukes fly back, the nuke units of Russia will be left intact for the new St. Petersburg gov to control.
The only reason you think MAD is still in play against Russia is because you are ignorant of how nuclear threats are actually detected and tracked, along with ignorant of how said tracking plays into calculations on whether to launch or not on the part of others.
You only think MAD is unwinnable because Hollywood and the media obviously don't talk about the successes of the ABM and BMD shield tests or the classified shit around them, only air power magazines and nerd forums.
No, you just are operating in massive ignorance of the realities around nuclear war in exchange for the outdated meme's around it.