This, a strategic study by the US Joint Forces Command, is a thoroughly fascinating read. The part of immediate interest is of course the section on energy, and the prediction of oil shortages made already in the introduction by the commander of the USJFC General Mattis.
“By 2012, surplus oil production capacity could entirely disappear, and as early as 2015, the shortfall in output could reach nearly 10 million barrels per day.”
And then this:
The rest of the text is equally interesting however. For starters, Mattis is a Marine, and the Marines seem to have been very interested in Fourth Generation Warfare lately. There are plenty of Sun Tzu references throughout, and the depth of the analysis is fascinating.