This is an issue that deserves more attention than it is getting. It speaks to a number of issues of interest: info ops, nukes, economics, society and resilience, among others.
The bad news is that an adversary capable of launching such an attack need not be perfect or even accurate; a blast “in your general di-rec-shun” is sufficient to be successful (physical destruction and fallout being a bonus from the other side’s point of view).
Given that there are few potential adversaries with such capability there is a tendency to push this issue to the back burner, but consider a notional scenario where such an attack is perpetrated by, say, a country where we get most of our electronics from in the first place. Replacing and rebuild our info-infrastructure? Sure, let’s just get on the phone to talk to the people who just zapped us …
As with so many issues of this import and scale, the fix is expensive and painful, which is why we can be fairly sure that if it does happen, we will be taking a very long time-out from the info age.