i'd be great if they did, at least on the West coast since it really doesn't feel like a post-apocalypse any more
B.O.M.B.-1 had 8 functional missiles onboard. depending on the type of missile and if it had a M.I.R.V. Payload, and the Yield of those warheads.. 8 missiles could take out anywhere from "most of California" to most settlements in the known wasteland, most ICBM's carry 3-5 MIRVs when In Multiple target mode so 1-3 missiles take out all of California and the rest can be used against the Mojave, Arizona, Chicago and the East coast
Eh... For the sake of keeping the post-apocalyptic feeling in the West, I just want political instability to happen. NCR collapse (or just diminishing to the capital) as well as a Legion collapse would do the trick. No formal road protection = lots of gangers. No doubt most of the cities would keep the same amount of order (I'm pretty sure they have a lot of autonomy even with NCR), but travel would be just as hazardous as Fallout 1-2 and some settlements could be taken over.
Nukes would be pretty damn superfluous.