This presentation by the Center for Security Policy is worth watching. The points that most impressed me were made by the former head of the Defense Nuclear Agency, the bureaucracy that manages our nuclear-bomb inventory. He pointed out that the inventory is old and that weapons need to be tested from time to time to insure their reliability, and that any test ban would therefore be incompatible with our maintenance of a reliable arsenal.
Furthermore, our nuclear weapons were designed to destroy cities and large, hardened missile installations and airfields and the like, and are much too powerful to be useful in today’s world. For example, we can’t plausibly threaten to blow up Tehran to discourage the mullahs from building nukes. Everyone knows we wouldn’t follow through. But if we had very-low-yield nukes built into penetrating warheads we could actually use them, and it would become possible for us to change the Iranians’ behavior without attacking (or by attacking conventionally and then threatening to use nuclear penetrators on Iranian R&D and production facilities if the Iranians didn’t scuttle their nuke program). But we aren’t building these small nukes, because Obama doesn’t want to, and even if he wanted to it’s difficult to produce a new generation of reliable nuclear weapons if we forbid ourselves the ability to test them.
(After the CSP video, C-SPAN showed video from a Global Zero PR event, perhaps for comic relief. Global Zero wants to apply the logic of domestic gun prohibition to global nuclear armaments. I am sure this concept will work as well with the Iranian mullahs as it does with common criminals.)