Why is BushCo so intent on attacking Iran?

Is it their sponsorship of "terrorism?" Is it the "threat" they pose to the US?

Or, to be more diabolical, is it the only chance of Republicans winning the next election?

No, I think it boils down to one word—Petrochemicals.

from Michael Klare in Tomsdispatch:

In the case of oil and natural gas, the major energy-surplus states can be counted on two hands. Ten oil-rich states possess 82.2% of the world's proven reserves. In order of importance, they are: Saudi Arabia, Iran, Iraq, Kuwait, the United Arab Emirates, Venezuela, Russia, Libya, Kazakhstan, and Nigeria. The possession of natural gas is even more concentrated. Three countries -- Russia, Iran, and Qatar -- harbor an astonishing 55.8% of the world supply. All of these countries are in an enviable position to cash in on the dramatic rise in global energy prices and to extract from potential customers whatever political concessions they deem important.

I assume you noticed which countries are numbers two and three...