Exxon was late getting onto the Caspian in the 1990s, but it still ended up with pieces of prime real estate. On the Baku side, deputy Energy Secretary Bill White interceded to get it a piece of the offshore after Exxon stood on the sidelines while its rivals slugged it out. In Kazakhstan, even GOP heavyweight Jim Baker couldn't persuade Kazakh President Nursultan Nazarbayev to grant Exxon a piece of the ultra-supergiant Kashagan oilfield; Nazarbayev told Exxon the bidding was over. So Exxon simply bought Mobil Oil, which itself was one of the best old-fashioned horse traders on the Caspian and had grabbed huge slices of both Kashagan and Tengiz.

Yet none of that meant that Exxon had drunk the Kool-Aid on the Caspian. It was the only member of Big Oil present in Baku to refuse Clinton administration entreaties to help build the geopolitically minded Baku-Ceyhan pipeline.

It's a similar story with Exxon's announcement yesterday that it's investing up to $600 million in an algae-to-fuel venture with genetic biologist J. Craig Venter. I wrote about this for Business Week on-line today. Exxon waited until Shell, Chevron and others dipped their toes into algae, then dove in with Venter, the most famous private genomics scientist in the world.

Quite apart from the long-shot chance that the venture could actually succeed, Exxon benefits from being able to brandish an environmental pin on its lapel, and its association with an authentic biofuels rock star. As Deutsche Bank's Paul Sankey told me in an email, "I think it's part R&D, part PR." Venter himself needed the cash injection, and could earn $300 million from Exxon if he meets certain unspecified project milestones probably associated with the economics of the algae.

The announcement included an ominous note as well as far as I'm concerned. It was that Exxon took this step after a deep-dive evaluation of every alternative fuels technology currently being studied anywhere. Apart from algae, it determined that none of the other potential technologies -- not manipulation of microbes, not the use of yeast, not breaking down cellulose with enzymes -- would produce a commercial product.

Much is said about Exxon, but one indisputable thing about the company in my opinion is that it is deadly serious when it comes to studying how to do something, or how to do something better. Its execution and management of complex energy projects is unparalleled in Big Oil; that is the singular reason why it's so profitable. So if Exxon tells us effectively that, of the currently studied technologies, only algae is going to survive commercially, the opinion must be taken account of.