Even if the asteroid is a carbonaceous chondrite, I estimate weight at 500 tons. It is nickel-iron it cold weigh over 1000 tons.
When used to fill reentry vehicles with individual guidance systems and reentering at 7 km/sec. you have the equivalent of several thousand tons of TNT delivered anywhere on Earth and without warning.
The NKs could not bury a facility deep enough to escape such a weapon.
The Chicoms have plenty of good engineers. The physics are simple.
He who controls the High Ground will win. It had better be America!
Oops, typos made in haste. Cold = could. It = if.
I’ve heard talk and speculation about that very idea, you have the speed and all you need is the mass and guidance.
Still, if you’re going to weaponize space it would be a lot cheaper to just build a stealth weapons platform with nukes than go through all that trouble, its not like you could do it quietly enough that the world wouldn’t know what you’re up to.
Robert Heinlein covered this decades ago in "The Moon is a Harsh Mistress".
TANSTAAFL!