The U.S. Army desert boots, used without problem since their first major workout in the 1991 Gulf War, are rapidly falling apart in Afghanistan. Soldiers complain that the boots fall apart after a few months. The problem appears to be that the boot soles and heals were built to deal with soft sand. Afghanistan has lots of sand, but also lots of sharp rocks, which tear the boot bottoms up. Apparently, the boot did not get extensive testing in rocky desert areas (which are not as common as mainly sand deserts.) Deserts have long been a major problem for developers of military equipment. Over the last 20 years, it has been discovered (the hard way) that the varying size of the sand grains in different deserts requires different filters for vehicle engines and power generators. It's difficult to make one filter that will deal with different kinds of sand. With boots, it may be a different situation. The U.S. Marine Corps recently developed a new desert/jungle boot (with the help of U.S. Army clothing developers) and is about to equip all marines with it. The army has not decided whether to adopt the new boot, and still issues either desert or jungle boots. The new "combo" boot apparently stands up to rocky deserts better than the desert boot.