Look. The Big Three (at the least) and probably a couple of more of the nuclear powers have bomb platforms in space. Without a doubt we, the Russians, and the Chinese have satellite borne EMP capabilities. Military thinkers take it as a given that any major nuclear exchange will be presaged by an EMP strike.
That's not the issue. If any of the Big Three use their EMP capabilities, all hell is out for lunch anyway, and the rubble will be jumping in TEOTWAWKI, Big Nuke Edition.
It's the terrorists with one or two lousy bombs and some sort of Scud-primitive way of getting them high enough.
That - and Carrington Events - are what we really need to be worrying about in terms of EMP. If an EMP strike is followed by three or four hundred nuclear weapons, EMP is going to be the least of our worries.