Malone, yeah, the world supply of oil is finite. I've seen no reason not to believe in Hubbert's Pimple*, even if the dates might be a bit off. There is reason to believe, however, that vast amounts of oil underlie areas around the Black Sea and in places like Kazakhstan.
As we develop alternative energy sources, we are yet needful of oil. Even if it's not used in transportation or in the production of energy, we still need the consumer products which derive from the petrochemical industry--such as the plastics in our myriad communications devices. Computers or cell phones, anyone?
There's no magic. Realpolitik sez that nations will do what nations gotta do in order to survive. The perceptions of the leadership come into play, here, of course, but whether Kerryite or Bushie, any administration will continue to follow the path that helps maintain our economy--and that means oil.
"Nations don't have friends; they have interests." is a fact. Realpolitik has no morals. It is oriented to survival--which leads, then to the question whether survival is a moral imperative.
Stipulate we'll be well on the downtrend of Hubbert's Pimple in (likely) thirty years. Is it not in our national interest to be in a physical position to have strong influence in the greatest oil-producing areas? And as to cost, is it not better to be in a country like Iraq than on the high seas with lesser capability but higher costs? I submit that force projection from bases in Iraq will cost less than force projections from the U.S., the Indian Ocean and the Mediterranean.
Note that I'm not assigning "good" or "bad" or moral values in general to any of these comments, here and earlier. National survival is more important to national leaders than winning football games was to Lombardi.
Art
* Hubbert's Pimple: M. King Hubbert was a petroleum geologist with the USGS. Around 1950 he charted his idea of the world's usage of fossil fuels, in the form of a graph. It showed a slight but steady rise from the first usage of peat and coal, adding oil after the first discoveries in the US, to a steep rise beginning in the late 1930s and peaking around 2010. The decline is as steep as the rise. The decline in use results from the decline in availability.