[denton-scratch]

Most modern high explosives won't detonate at all in response to a kinetic insult. They need a detonator, and usually a primer too. Even TNT; you can hit it with a hammer, shoot at it, or try to set it on fire; it won't explode. To set it off, you need a supersonic shockwave.

[escape_goat]

To my circumstantial understanding, it is plausible that fragments of an interceptor detonated in proximity to the warhead could achieve supersonic velocities capable of delivering the requisite shock, but I lack the knowledge to argue the point.

[BenjiWiebe]

And it'd still need to detonate the difference sections in exactly the right timing to get a successful nuclear explosion.