It's all about oil

What kind of threat would Iranian nuclear weapons make? A militarily effective nuclear weapon, that is one that can be delivered to target, would need to be fitted onto a ballistic missile in the absence of air superiority. The main missile here is the Shahab 3, which is Iran’s variant of the North Korean Nodong. Pakistan’s Ghauri II is also a variant of the Nodong. If Iran were to manufacture nuclear weapons then it would weaponise the Shahab 3, but doing so (given the large payload compared to a conventional explosive warhead) would seriously affect the missile’s range and accuracy.

At best this would give Iran a regional nuclear deterrent. It would not have the capability to deliver a nuclear warhead either to Europe or the United States. Nuclear weaponisation of the Shahab 4, reputed to have inter-continental range, is fantasy talk.

Therefore if Iran were to have nuclear weapons they would act as a deterrent against US intervention capabilities in the region, not against the US homeland, containing most of the world’s energy resources.

The eventual wash-up of the invasion of Iraq may lead to the formation of a semi-integrated Shiite bloc in the Gulf region. This could include Saudi Arabia’s most lucrative oil fields, which contain a sizeable Shia population. Any Iranian nuclear weapons would then take the form of a deterrent preventing Washington from breaking up such a consolidated independent entity by force. If so, the US would have effectively lost control of most of the world’s oil.

This is what is at stake and US actions with respect to Iraq and in relation to Iran is making such a possibility more likely. Indeed, if Washington is rattling the sabre against Iran because of its failures in Iraq then it would only greatly compound the original folly of invading Iraq.