From the Wall Street Journal:

DECEMBER 6, 2011

U.S.'s Afghan Headache: $400-a-Gallon Gasoline
Military Air Drops Fuel Barrels to Avoid Dangerous Convoys

OVER EASTERN AFGHANISTAN—Parachuting a barrel of fuel to a remote Afghan base takes sharp flying skills, steady nerves and flawless timing.

It also costs a lot of money—up to $400 a gallon, by military estimates.

But the Pentagon is stuck with the expense for the foreseeable future, especially given the recent deterioration in U.S.-Pakistani relations.

The sheer volume of air-dropped cargo is swiftly rising. In 2005, Air Force planes dropped around two million pounds of supplies to troops in Afghanistan. Last year, they delivered around 60 million pounds by airdrop. By the end of this year, officials say, they expect to drop around 90 million pounds of food, water, ammunition and fuel to bases in the country.