The article claims that a nine-megaton blast would wipe out "most of the state of Arkansas". Wikipedia claims the lethal radius on a bomb of that size is about 20 miles for thermal effects ( http://en.wikipedia.org/wiki/B53_nuclear_bomb#Effects ), which is around 2% of the area of Arkansas; other effects are described as having an even smaller radius. I suspect, but cannot prove, the wikipedia number is more likely t…
The Wikipedia number is not correct, because even a single blast has long term consequences, and in a full scale war, the consequences are more significant than the initial damage.
Even if the blast was just one a of a handful, survivors would have to contend with fallout from other detonations, followed by nuclear winter, followed by years of famine, mutation, cancer, and other diseases.
In a full scale war, nukes are targeted at nuke power plants, so there would be even more fallout - enough to sterilise many parts of the US.
Initial casualties would be a small percentage of the eventual total.
Even a limited exchange in a distant part of the world would have global consequences. See e.g.
http://phys.org/news/2013-12-nuclear-war-civilization-famine...