Agreed we as a nation will retain the knowledge & while we as a nation would be knocked on our national asses for a while unless the rest of the world also suffered a EMP attack getting replacement parts would take a short while but once the lights started to come back on there would be a lust for vengeance against those that attacked us that would lead to somebody getting the Carthage treatment.
GOD help any politician or leftist/anarchist pudding stirrer that tried to say we had it coming cause they will literally get ripped to shreds .
An EMP attack will NOT affect missile submarines (or their missiles). Payback will happen virtually instantaneously. No need to wait 'til "...the lights start to come back on...".