Nothing to do with Islamic fundamentalism (at least on the part of the United States), the Taliban, or terrorism. This article makes more sense:
The development of the Russian oil industry in Salkhallin, an island almost the size of Japan and other areas of the Russian Far East, combined with Central Asia's oil reserves, will be more than sufficient to replace Saudi Arabia, Kuwait and the other OPEC producers of the Middle East in their entirety as far as future U.S. strategic energy requirements are concerned.
I knew that Afghanistan was more important as a site for crossroads than as a thing-in-itself. What I didn't realize was the size of the strategic reserves in the 'Stans. Yes, Iran has interests in keeping a front going against Sunni Islam (yawn), but this is bigger than that, given that, as I understand it, Sunni Islam controls more oil production than Shiite Islam does. With controlling interest in the country that is a key crossroads for all those pipelines, Iran would become a kingmaker in global terms.