beardy.
You are right about the plasma issue. But it is well-known for decades since the problem to communicate with descending spacecraft crew had arisen. Many successful research and experiments were undertaken recently in US, Russia, China and even Germany. No idea if anybody implemented any solution in a real thing, but all this seems doable.
Also no idea why there are some hysterics about long-range missiles mentioned by Putin (though I think he should not have talked about this publicly).
Nuke-powered cruise missile is a "grand-dad stuff". I recall I read about it being a kid in mil. academy. Here are a couple of links:
https://en.wikipedia.org/wiki/Supers...titude_Missile
https://www.newscientist.com/article...drawing-board/
And "highly" manoeuvrable ICBM warhead is not an advanced thing to do for the industry that was launching "shuttle like" spacecraft some 30+ years ago.
As for "Armageddon", radiation will not be the major killer, but global "N-winter". Even NZ would not give a shelter.