Nuke proliferation has remained far slower than the experts have predicted for more than half a century now. Ever since I am a kid I have been told we are just years from 20-30 powers, and yet Iran will make only ten. If Turkey and the Saudis followed suit, that would be 12. There is simply no prospect of even two dozen on the horizon.

Among the established nuke powers, there is no sign of irrationality overcoming precedent, so we are left, as always, with newcomers and nonstate actors. Does anybody posit massive nuclear exchanges on this basis? No. Do we wrap our entire grand strategy around the axle around the singular event? Some would have that.

I would not.

Iran and Israel exchange nukes and nothing much would change. Indeed, the rule set would likely be overwhelmingly strengthened.

We cannot stop every act of irrationality on the planet, nor should we fear it. We should simply take it in stride and stick with our own calculations of interest.

As for bringing up 1914, pre-nuclear examples of world war don't work in a post-nuclear world. You can't roll back the clock. You can't get rid of the crystal ball effect provided by nukes. You can't un-invent them.

And it's deeply misleading to cast colonial empires as the equivalent of today's globalization. Comparing the two casually is like comparing apples and handcuffs. The uncompetitive movement of resources from colonies to home countries does not compare to globally integrated production. Enslaved populations do not compare to a global middle class. Telegraphs controlled by governments don't compare to 3-billion and growing cellphones held by individuals.

Colonial empires were zero-sum developments, both in terms of the enslaved and in terms of competing with each other. No surprise the empires eventually turned on each other, and good riddance.

But what should I live in fear over that outcome in today's world?

We just lived through a financial crash very similar to the one that triggered the Great Depression. The difference in global outcomes was profound, was it not?

Me:

As my comment elicited Mr. Barnett's response referred to in this post, I would just state that while I believe he is laregly correct thus far in his assement of contemporary global events and interdependence; to assume this will remain inevitably so seems too optimistic.

Nuclear weapons have historically kept a lid on "Great Power" conflict since the end of World War II, at least in the sense of "Hot Wars." However, we have never had a world of numerous nuclear powers, much less a world of nuclear powers of various stability and security capabilities. As proliferation takes place, more rapidly now than over previous decades, we can not be sure what might happen afterwards.

Mr. Barnett states:

"Iran and Israel exchange nukes and nothing much would change. Indeed, the rule set would likely be overwhelmingly strengthened."

Why would the rules be strengthened rather than weakened as the long-standing taboo is broken? Because the world would get another demonstration of nuclear weapons terrible effects? Or will we see more people looking to amplify their ability to counter so they are not unwittingly on the end of an exchange?

We just can't tell how it would turn out. That is why we must prepare for the worst, even if it seems unlikely.

I sense an element of triumphalism in Mr. Barnett's comments- that all we have to worry about is small ball and integrating those currently not in the full blown "Core." He seems to think the belief in possible Great Power conflict is naively outmoded and that nuclear terrorism will not be all that big a deal as the world will pretty much go on as it always has the day after such an event.

I think hyperventilation over these potential threats is not necessary, nor strategic. However, I also think failing to consider their full implication could leave us ill prepared to handle the fall out should they actually transpire.

We don't live in 1914. That was never my point. My point was to simply illustrate that assumptions made one day can change dramatically and diametrically based upon a single discontinuity."