For all the talk of America’s growing reliance on computers, advanced sensors, and stealth technology to prevail in warfare, it has been oil above all that gave the US military its capacity to “project power” onto distant battlefields like Iraq and Afghanistan. Every Humvee, tank, helicopter, and jet fighter requires its daily ration of petroleum, without which America’s technology-driven military would be forced to abandon the battlefield. No surprise, then, that the US Department of Defense is the world’s single-biggest consumer of petroleum … The average GI in Iraq now uses about seven times as much oil per day as GIs did in the first Gulf War less than two decades ago. And every sign indicates that the same ratio of increase will apply to coming conflicts; that the daily cost of fighting will skyrocket; and that the Pentagon’s capacity to shoulder multiple foreign military burdens will unravel. Thus are superpowers undone.