Bill, you misunderstand me. I don't underestimate the damage that could occur during a major event, what I disagree with you about is our ability to recover from such an event or the all encompassing nature of such an event.
I think if you look at the records from the last Carrington Event, you will note it WASN'T so all encompassing, as to affect the entire planet in the same way. Sure, the western part of North America was hit the worst, but what about the rest of the planet? Where are the records of what happened in Europe or China? Or even the East Coast of North America or even Central America?
You can't tell me of anything more serious than flashing lights in the skies over regions that had just as much technology as the US had. The biggest hallmark that I see about the Carrington Event, is that it was limited to an area, a huge area, but still limited to an area.
And if an enemy were to use enough energetic devices as to saturate the planet, we'd have a lot more problems to deal with rather than merely losing our electronics,
There is no geological evidence of such an event taking place over the planet, at the same time. All there are, are Possible shifts in the magnetic field, and if anything ever took place at the planetary level as you postulate, believe me, we'd have some evidence of that. I believe massive events have taken place in the past, just not over the entire planet, at the same time.
You should be glad, it makes the probability of another strike from the Sun, very unlikely, in the Western US. Yes, it was a huge area, that was hit, but not even all the Western parts of North America were hit with the same amount of power, and that's why the evidence of what happened during the Carrington Event, is primarily historical rather than physical.
So yes, I believe that such an Event will take place again, but I also believe you are over-generalizing, to make it such a planet encompassing event. Yes, it will hit somewhere on the planet with devastating power, just not everywhere on the planet, at the same time. For the Earth to be hit with as much energy as you are postulating, it would have to from a SuperFlare, and while there are observations to indicate such are possible on other sun-like stars, we haven't seen anything even close to such a phenomenon on our sun or any remnants on the other planetary bodies of our system.
It is my belief that enough other parts of the Earth would survive either a man-made or natural event, that we COULD recover and rebuild. But we can't afford to twiddle our thumbs, in the hope we won't be the target, by either man or nature, we must prepare for such a possibility, it's just the scale that you postulate, that I disagree with. For if we were to be hit with the amount of energy that would be necessary to saturate our planet, we would have some rather severe biological effects to worry about, not just technological, and I'm not sure if the human race could survive that, even from deep shelter.