that’s only a couple of thousand miles. Then there is the Pentagon. Typical Russian missile speed, 15,000 mph, maginally sub orbital.
Now look at a map of Russia (Novosibersk) and distance from a coast.
I still don't get your point. ICBMs are tracked to attack over the pole not from E-W. Distance from either coast is moot.
There have been hypersonic missiles for 80 years. The V2’s the German’s launched against Britain were hypersonic. A Patriot battery shot down half a dozen Kinzhals over Kieve earlier this year. There is nothing magical, mystical, or particularly new about missiles that travel 5X the speed of sound. In a real war the Kinzhals have to be launched from aircraft and in a war with NATO there would not be any Russian aircraft after the first week so unless we are talking a first strike attack in a nuclear war which would produce a nuclear winter that would destroy Russian agriculture and from which nobody would “win” the Kinzhals are irrelevant. The real problem is Russia and the west tit for tatting their way into an all out war from which again there would be no winner. Russia has not hardened its airbases and planes sit out on the apron east targets that would be wiped out quickly.
https://www.brookings.edu/articles/ukraine-and-the-kinzhal-dont-believe-the-hypersonic-hype/