The headquarters of the International Security Assistance Force (ISAF) in Kabul looks more like a college campus than the nerve center of a military operation involving more than 90,000 troops from 41 countries, its staff officers roaming the halls in each nation's distinct patterns of camouflage. On July 3, on a wooden deck at the back of his office in the compound, shaded by trees and a garden umbrella, U.S. Army General Stanley McChrystal, who recently became ISAF's commander, and that of U.S. forces in Afghanistan, sat down to discuss his new role. Tall, lanky and earnest, with the loping stride of a long-distance runner -- McChrystal runs 10 miles before his morning coffee -- the general went to Afghanistan after a top job with the Joint Chiefs of Staff in Washington. He knows Afghanistan well. The conflict there, McChrystal told TIME, is a "tough war, a very tough war."