When I was in Washington on Tuesday Miles Pomper, who's a Senior Research Associate of the James Martin Center for Nonproliferation Studies, asked a good question at the book event for Elements of a Nuclear Disarmament Treaty. "The US doesn't need nukes because it can use precision guided munitions," he said, echoing a point in my presentation, "but what if you're a poor country. Doesn't it make sense to have nukes if you don't have the technology for precision guided munitions? How are you going to reliably blow stuff up without nukes?"

It's a good point. The United States doesn't need nukes because we have a far more sophisticated military with lots of other tools in our toolbox that can get the job done. But what if you don't have this expensive, technologically advanced toolkit? Don't nukes make a suitable replacement?

I think the answer is no. There are several reasons. First, building and maintaining nuclear weapons is enormously expensive. If you're going to spend that kind of money, you might as well build missiles and expensive guidance systems. You can buy cruise missiles and have a fairly reliable alternative for a lot less money.

If you use a nuclear weapon to take out a key military target - a command center in a city, for example - you create a number of problems. Nuclear weapons, because they are so large and clumsy, will necessarily kill a large number of civilians. This will have two consequences: 1) it will harden the resolve of your adversary almost to the point of fanaticism and 2) it will create enemies for you abroad.

People always imagine that using nuclear weapons will cow opponents. But killing civilians almost never leads to surrender. I won't say it has never happened. But for all the civilians killed in war the number of surrenders directly motivated by those killings approaches zero. Far more common is a spike in desire for revenge, increased enlistments, and hardened resolve. The attacks of 9/11 didn't inspire calls for surrender. They made people angry and filled with rage. A nuclear attack would kill far larger numbers of civilians than were killed in the United States in 9/11. Imagine the emotions created by 9/11 multiplied by a hundred. That's a lot of determination.

Also, attacks with nuclear weapons create problems around the world. The countries that felt inclined to ally with you draw back, the countries inclined to come to the aid of your opponent feel more inclined to do so. Possibly you incite countries to come into the war on the other side. You certainly create long term distrust and dislike in the world community. Bringing additional countries into the war against you is potentially disastrous. Creating long term enmity is a serious drawback.

So it seems to me that even if you didn't have the ability, as the United States does, to use precision guided munitions as a substitute, that it still wouldn't make sense to build nuclear weapons. You'd be far better off spending your money on conventional weapons that were not as clumsy and that had fewer negative side affects.

I don't think I had thought this through in my mind and Miles' question pushed me to do that. Thanks Miles.