The other two major justifications are the related threat of the coming "oil peak" and disruptions in world energy supply, and the climate change threat from continued burning of fossil fuels. All three lines of reasoning call for reductions in oil use, though they may be at odds on other issues (for example, switching to coal for the US may satisfy the first two for a time, but worsens the third; satisfying the first requires a drop not only in oil use, but in oil prices as well).
The geopolitical angle, which Friedman has been pushing for over a year, hinges on the fact that huge portions of oil profits go to Middle Eastern regimes that may then use the money to fund terrorism or repressive governments. In his latest column, "No Mullah Left Behind", the regime of interest is Iran, where oil money has apparently stifled needed economic reforms, and funded nuclear developments.
Friedman points out that Bush administration policies are effectively funding both sides of the war on terror:
We are financing the U.S. armed forces with our tax dollars, and, through our profligate use of energy, we are generating huge windfall profits for Saudi Arabia, Iran and Sudan, where the cash is used to insulate the regimes from any pressure to open up their economies, liberate their women or modernize their schools, and where it ends up instead financing madrassas, mosques and militants fundamentally opposed to the progressive, pluralistic agenda America is trying to promote.
Friedman has dubbed the geo-political viewpoint on energy "geo-green", and the measures he calls for are even more dramatic than some we have considered here: "sharply lowering energy consumption and embracing a gasoline tax" of $1 per gallon. Friedman also suggests a role for campus activism, as highlighted by WorldChanging maven Jamais Cascio, to force auto-makers to improve gas mileage.
Friedman clearly has some good ideas here; the fact that his approach is independent of environmental or resource-limitation advocacy gives it an interesting currency in the US political scene. Is "geo-green" sufficient common ground for actual progress to be made on alternative energy? Or will it just lead us down another dead-end of coal or nuclear-dependence? Friedman's $1/gallon goes far beyond Smalley's suggested "5 and dime" solution - is there any chance it could actually happen? Even keeping a small portion of that tax revenue for alternatives research would make a huge difference.