A nuclear Iran is likely to give or lend nuclear weapons to terrorists, resulting in an undeterrable nuclear strike against an American city or cities.
And the answer to this dread scenario? Why,
a credible threat of force.
Eh? Employing a credible threat of force is only useful if the party you threaten cares about it – in which case they will either be compelled to do something or deterred from doing something. Which adds up to the same thing. If they are undeterrable, a credible threat won’t cut it – only the force itself will. Deterrence is a way of seeing strategy that assumes a world of realpolitik. In the title of the classic textbook, it’s all about people, states and fear.
Traditionally, this is why the Realist school of thought loves deterrence. There is a lot to be said for Classical Realism, even though this does not make one popular on the left (ask Justin of Chicken Yoghurt fame) – for a start, one of the key insights from it is that starting wars is usually very stupid. Another really important point about realpolitik is that the crucial assumptions are that people and states are actually very alike. We are all human, fallible, and terrified. And we all seek to be less terrified.
Compare the worldview in which there are some people who not only cannot be appeased, they cannot even be deterred. That is to say, they don’t even share the human emotion of fear. Even Hitler was deterred from a few things – he didn’t use chemical weapons on London or the Red Army, chiefly for fear that we’d “drench Germany with poison gas” in Winston Churchill’s words, and he didn’t attack Malta, though it would have been a big strategic gain, for fear of losing the Parachute Corps.
There’s a long tradition of this stuff – people who have no respect for their own lives, Asiatic hordes, barbarians, ultramontanes. Mao even applied it to his own side. Blue ants, he said. What a lot of the historical instances have in common is that it usually comes before an attempt to exterminate the people so described. After all, if they are a horde without fear, who cannot be deterred, they aren’t really people..are they?
Iran, for its part, already has a strategic deterrent capability. It’s called oil. As well as its own exports, it has a very significant missile capability (to say nothing of all those hordes of suicide bombers the war party claims) designed to sink tankers and attack Saudi and Kuwaiti oil loading infrastructure. In current market conditions, I would seriously wonder whether a 2 kiloton or so nuclear explosion would not do less damage to the West than an extended disruption of Gulf oil shipments. There’s also an operational level deterrent – remember those 140,000 US soldiers and marines in Iraq? They are mostly concentrated around Baghdad and to the north-west, with a main supply route running out of this concentration through the Shia heartland parallel to the border with Iran. The US Army and Marines in Iraq are formed to a flank operationally, and heavily dependent on the British Army down south to hold the line and the SCIRI to stay quiet.
But the war party does not seem to be worried by this. Why aren’t they deterred? They are irrational! Maybe we should..
Another point, in passing. Why would anybody think that a state, having just achieved a gigantic national project employing the best of its scientific-technical elite, the undivided attention of its military-industrial bureaucracy and vast sums of money, in the teeth of the world’s great powers – would instantly give the thing away? States don’t behave like that. No states do. Pakistan didn’t. Neither did North Korea, and if you think North Korea is any less crazy than Iran..