"Mr Ahmadinejad has already threatened to respond to any UN sanctions against Iran by turning off his country's oil supplies."
That is just a bluff, since they need the revenue.
Maybe.
Remember this is a small, thin man, who grew up in poverty and mainains it as his profile. It would not be far removed for him to think that if he and most of the nation live on the verge of poverty, nothing much would change in daily lives - as opposed to interaction with the rest of the world.
Remember Pol Pot and re-evaluate Ahmadi-Nejad's fears or need for the revenues. Specially when apocalypse is an accepted, encouraged aspect of his religious and philosophical beliefs.
They arent bluffing, Look at North Korea, They sell drugs and counterfeit money and goods. Iran can do the very same thing.