You think we can? I'd like to hope so, but we seem to be getting mixed signals from the talking heads.
I'm quite confident that we can take out any long range missile that is headed in our general direction AND manages to get out of the atmosphere. I don't think we have a reliable boost-phase antimissile capability.
At this point, the answer is "maybe". But those in the know aren't going to be saying so just yet. How long was it between the first Stealth Bomber scuttle and the final announcement that we had them and they worked REAL well?