http://madconomist.com/what-if-us-collapses-soviet-collapse-lessons-every-american-needs-to-know
"One such untenable arrangement rests on the notion that it is possible to perpetually borrow more and more money from abroad, to pay for more and more energy imports, while the price of these imports continues to double every few years. Free money with which to buy energy equals free energy, and free energy does not occur in nature. This must therefore be a transient condition. When the flow of energy snaps back toward equilibrium, much of the US economy will be forced to shut down."
"One such untenable arrangement rests on the notion that it is possible to perpetually borrow more and more money from abroad, to pay for more and more energy imports, while the price of these imports continues to double every few years. Free money with which to buy energy equals free energy, and free energy does not occur in nature. This must therefore be a transient condition. When the flow of energy snaps back toward equilibrium, much of the US economy will be forced to shut down."