There's no rocket left after the boost phase. Everything separates off but the warhead and its encapsulating reentry vehicle -- a compact, tough shell designed

There's no rocket left after the boost phase. Everything separates off but the warhead and its encapsulating reentry vehicle -- a compact, tough shell designed to protect it from the stresses of reentry. So it's probably far from fragile. Here's what those look like: https://en.wikipedia.org/wiki/Multiple_independently_targetable_reentry_vehicle#/media/File:W87_MIRV.jpg https://en.wikipedia.org/wiki/Multiple_independently_targeta...