The only two data points we have for nuclear weapons employment were against a culture with a near-fatalistic sense of duty and a tradition of subordinating one's will to that of the group.
Against Americans...I would argue that our greater emphasis on individualism will tend to create a much more chaotic reaction.
If anyone in the target area knows anything about nukes, but doesn't know anything about how to shield against fallout, he will attempt to get the hell out of there immediately.
Meanwhile, a bunch of folks, ignorant of nuclear weapons effects, will try to get their injured fellows (or themselves) to medical attention. Remember, communications are going to be OUT. Passing information to the populace is also going to be difficult, because many of them will have ruptured eardrums.
You basically are betting the mortgage money on a perfectly rational response, in the absence of perfect knowledge of what the rational response is.
I think the next closest comparison would be the English during WWII. They not only had area bombardment but a steady rain of V1 and V2 bombs. They were fairly well behaved. Every day Israelis are subject to sudden death from suicide bombers but they take it in stride.
Again it depends on the city. Fargo ND will react differently than New York City. I think a lot will have to do with public estimation of the danger. The Soviets had the capability to kill hundreds of millions of us yet we knew they didn't have the will. We can assume that terrorists would kill us if they could, but don't have the nukes -- and if they do, they won't get many.
Other data points would be cases were populations were sufficiently threatened when the Nazis were on the march in WWII. In those cases the exodus was orderly and rational, not rampaging mobs.
You are right, how people in the other cities react depends on what they know and the more they know the better. Different personalities will react differently -- some will leave, some will dig in and stock up. But the rational person will ask, where will I go, and what will I do when I get there? If you don't have a good answer you will stay put.
So there is no evidence outside of Hollywood that chaos would ensue.
Remember, communications are going to be OUT.
Why? EMP? What is the EMP effect from a ground detonation. I thought that was only a factor from high-altitude blasts.
Transistor radios will still work and radio stations outside the area will work.
You basically are betting the mortgage money on a perfectly rational response
That's the nature of life. We are forced to bet one way or another.
What's the alternative?