Besides air drops and Pakistani delivery routes, the U.S. military can transport cargo overland through a road and rail network called the Northern Distribution Network, which brings non-lethal supplies in through Central Asia.
We were certain that this was just a "pie in the sky" concept, but apparently engineers are hard at work designing those futuristic space elevators that promise to eventually whisk cargo and humans to the final frontier at a fraction of the cost of rocket-based delivery systems.