[Pessimist]

“Seems highly unlikely. EMP would not destroy the entire infrastructure, just the local area”

Yeah, I think the threat from EMP is sometimes overblown.

Long haul internet lines are generally fiber optic, and immune to EMP.

On the other hand, not many vehicles will start today without their ECU. Even diesels.

Does anyone here (other than doomsday scare type people) have any real data on the threat radius from the best EMP burst thus far?

[GOPJ]

I heard some years ago that an EMP 125 miles above Nebraska would knock out most of the Continental United States.

[brityank]

Does anyone here (other than doomsday scare type people) have any real data on the threat radius from the best EMP burst thus far?

Here's a collection of some detailed info from various sources, most of which matches my basic understanding from USN electronics training. If - big if - it happens all the major cities and a lot of the smaller ones are toast. Plan accordingly.

Declassified data on effects of nuclear weapons and effective countermeasures against them

[wolfcreek]

“Long haul Internet lines are generally fiber optic, and immune to EMP.”

Won't matter, the source, the relays and your PC are susceptible. Then there's the electrical grid.