[U-238]

200 bombs is around how much we have in European bases. A realistic exchange is a 5000 megaton exchage between the Russians and United States. Counting primary and secondary targets in United States there are about 6,000 primary targets. These targets include: ICBM silos and launch centers, air force, navy and army facilities, key military support industries, command and control centers, and political infrastructures.

[U-238]

You will also have to include as possible nuclear targets priority on industrial targets which support the military effort including key military support industries, port facilities, fuel refineries, fuel storage facilities, power generating plants, chemical plants and communication facilities.

[wolf78]

200 bombs is around how much we have in European bases.

I used the number as an example because it's about as much as each France and the UK have. I don't think 200 nukes for the US would be realistic. Neither do I think the 300-400 nukes scenario would be.

A realistic exchange is a 5000 megaton exchage between the Russians and United States.

Yes, but how realistic is it? 5000 megatons is pretty much a doomsday scenario, it's a fight over who gets to be king of the trashheap. I can imagine a limited nuclear war in India or Korea with a dozen or so nukes. But when it comes to the US and Russia, the real significance of the nuclear arsenal lies in its hypothetical power and the way it can be used to influence other nations' way of thinking.

So TO ME the most important question is: how to maximize the psychological effect?

If you actually have to use your nukes, it's game over anyway.