That’s really helpful. Kinda amazing how it can avoid a laser by going fast.
That whole speed of light (laser) versus the fastest rocketry possible will have only 1 outcome. Yes we do.
Laser's aren't magic. The beam propagates at c or some appreciable fraction thereof (the atmosphere is not a vacuum), but, the question is the quantity of energy delivered per unit time.
There are several factors.
1) The wattage of the laser pulse.
2) The amount of time the laser is fixed on substantially the same patch of skin on the missile (raking a laser from top to bottom might not impart enough energy to any one square inch, what have you, to penetrate, or even to cause the skin to blister -- at these velocities, any asymmetry in airflow over the missile body would be catastrophic for guidance, if not immediately fatal to the airframe).
3) The composition of the missile's skin.
4) The angular velocity of the missile relative to the gun : for a head on approach, the bearing is constant, but the closer the missile gets for any nonzero offset, between the missile's path and a straight line between missile and laser, the FASTER the laser mount will have to swivel to keep its beam on the missile. For some orientations, the laser will have a very limited time to engage before the missile has just whizzed on by.
...and don't forget the strategic implications of flight time for early warning / evacuation of the President before impact. The only saving grace here, is that it is quite unlikely that anything like Tsar Bomba would fit on the cruise missile airframe.
...and, come to think of it, the faster the missile, the more precisely the detonation sequence will have to be matched to the missile's known or calculated position. Recall that at 3600 mph, you're going a mile a second. This will likely only be an issue for high precision targets; and these missiles are envisaged as strategic weapons, i.e. city busters.
I think it means that it is either very low altitude OD it has the ability to maneuver at high speeds. Most MIRVs are ballistic and fall in a pretty computable path.