Do you think that Iran is trying to achieve a Nuclear Weapon in order to deter being attacked by the United States?

In an article by Glen Greenwald for Common Dreams, states that Republican Senator Lindsey Graham has publicly stated that the US does not want Iran to achieve a Nuclear Weapon because it would bring a halt to the US aggression in the Mid-East.
A link to this article
http://www.commondreams.org/view/2012/10/02-5
When you stop to think about it, it does make sense… especially when you consider Bush & Cheney’s invasion of Iraq, which absolutely left Iraq devastated, with hundreds of thousands of Iraqi people who were killed. For all that think that the President of Iran, Mahmoud Ahmadinejad, is dangerous – that is probably true, but that does not necessarily make him a fool. He knows that a Nuclear Weapon will stop the US in our tracks. He knows that having a single Nuclear Weapon (even though he KNOWS that he is massively out-gunned by the number of Nuclear Weapons that the US has at its disposal), he knows that if Iran has even ONE Nuclear Weapon (with which he can retaliate if Iran is attacked) – it will make Iran’s position in the Mid-East much better. But to hear a US Senator say something like this in public, it makes one wonder what he is saying in private? Is the US that far gone down the road towards constant warfare that we are no longer able to even envision the US if it does not include a constant state of WAR?