[ArrogantBustard]

These interceptors we have now use conventional explosives? right?
No. No explosives at all. They're impact kill. At near orbital speeds, the kinetic energy in the warhead and the interceptor is more than enough to vapourise both.

Would they not be more effective if they had nuclear tips?
Not really. Anti-aircraft of anti-balistic-missile nukes were intended for wiping out large formations with one shot. The downside is that your defensive nuke sets of an EMP over your own territory.

[dimk]

Would be not easier to hit the enemy warhead with "close-enough" nuclear detonation then hitting dead on? I have no idea what is "close-enough" in this case but probably 1km radius at least? EMP should fry any electronics in the re-entry vehicle?

About setting off EMP over US, these interceptors supposed to hit enemy missiles before re-entry which is far away from continental USA.

The whole Kinetic destruction program sounds a bit PC inspired. I can see the value in a plane based laser anti missile system for theater defense, but attempting to hit enemy missile that probably has countermeasures, decoys and might carry MIRV just seems unreasonably hard.

The atmospheric ban treaty shouldn't be that much of a problem from underground test result it is easy to build a model of what warhead will do in space or in atmosphere. Then just test missiles trying to bring them close enough to the target, test triggers etc without a live nuke. This sort of system sounds much more practical.