I remember Bernard Lewis explaining to everyone how "ver Arab mind" meant that if we invaded Iraq, they would be so impressed with our might that it would all be roses, pretty girls, cheap fuel and democracy from Marrakesh to Lombok.
Personally, I think "deciding whether or not to launch a war of choice in the most politically unstable place on earth on top of 60% of the world's oil reserves or some such" is a career-critical function.
The CIA's official estimate, I believe, has Iran 10 years from a nuclear bomb. They base this on the opinions of nuclear engineers and overhead-imagery interpreters. I think I'll take that over Lewis's crystal balls.