Iran is the worlds fourth largest oil producer. Globally, there is very little spare oil production capacity. Any action against Iran which caused Iran and/or countries sympathetic to Iran to reduce oil production would send oil prices sky high. As with the Saudi oil embargo in the 70's, this would be very disruptive to world economies. Iran knows this, which is why they are feeling so bold about the nuclear issue.
So, when talking about acceptable risk consider: Is our extreme dependence on imported oil an acceptable risk? Let's hope President Bush means what he said in his State of the Union Address and does something about it.
