re: All your MERVs are belong to US, mabye....
I'm not expecting rogue nations to be able to deploy serious MIRV capacity any time soon. I don't think this was a "fish-barrel" test. In fact, the military deliberately lowered expectations by announcing ahead of time that they were testing various elements of the system, and that an actual impact was not one of the primary goals.
In other words, it worked better than they thought it was going to.