Why would the US Military and the IEA have contradictory oil supply outlooks?

US military warns oil output may dip causing massive shortages by 2015

..."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," says the [Joint Operating Environment report from the US Joint Forces Command]...

It adds: "While it is difficult to predict precisely what economic, political, and strategic effects such a shortfall might produce, it surely would reduce the prospects for growth in both the developing and developed worlds. Such an economic slowdown would exacerbate other unresolved tensions, push fragile and failing states further down the path toward collapse, and perhaps have serious economic impact on both China and India."

The US military says its views cannot be taken as US government policy but admits they are meant to provide the Joint Forces with "an intellectual foundation upon which we will construct the concept to guide out future force developments."

...The Paris-based International Energy Agency remains confident that there is no short-term risk of oil shortages but privately some senior officials have admitted there is considerable disagreement internally about this upbeat stance.

Future fuel supplies are of acute importance to the US army because it is believed to be the biggest single user of petrol in the world.

...Glen Sweetnam, main oil adviser to the Obama administration, admitted that "a chance exists that we may experience a decline" of world liquid fuels production between 2011 and 2015 if the investment was not forthcoming.

...The Joint Operating Environment report paints a bleak picture of what can happen on occasions when there is serious economic upheaval. "One should not forget that the Great Depression spawned a number of totalitarian regimes that sought economic prosperity for their nations by ruthless conquest," it points out.

Terry Macalister
 guardian.co.uk, Sunday 11 April 2010