Aviation Week & Space Technology, 05/29/2006, page 19
The U.S. Missile Defense Agency and Navy say they've conducted the first intercept of a ballistic missile in its terminal phase, using the Aegis system and a Raytheon-made Block IV Standard Missile-2.
The test occurred May 24, and the interceptor hit the target in the final few seconds of flight.
I seems to me that we have moved fron on extreme to the other on BMD technology. In the 1960 we developed the Nike-X system that had nuclear interceptor. The exo-atmospheric Spartan had a 5 megaton bomb. Well this would cause all sort of radar blackout and EMP effects that would be damage our own systems (and civilian infrasturture as well).
So then we go to totally non-nuclear hit-to-kill from the 1980s on if we don't pay much attention to the X-ray laser. It seems to me that if we used the current capability of the hit-to-kill systems and coupled them with low-yield enhanced radiation warheads (about 1 kiloton) we could greatly increase our probability of kill while avoiding the massive blackout and EMP that the Spartan would have yielded.