PeterUK – the problem with deterrence in the modern world is knowing who attacked you. Iran would do it through proxies. Al Qaeda, of course, would be happy to be a proxy.

If a bomb goes off, what do we do and who do we do it to?

This is why proliferation is such a serious, non-linear problem. It changes the nature of the problem from the simple one of nuclear deterrence against a missile delivered nuke, to the complex on of being willing to destroy whoever nuked you, when you don’t know who that was.

In a proliferation scenario, the deterrence strategy falls apart. You either kill a very large number of relatively innocent people, or you let someone get away with it.