Kolhatkar: In the 14 years it has occupied Afghanistan, America’s longest war has achieved mostly bloodshed. Despite spending billions of dollars—the U.S. offered its largest share of foreign aid to Afghans last year—there is little to show for it. Nearly $10 billion was spent on arming and training Afghan forces. But as the dismal state of the Afghan National Army shows, that money may as well have been poured down the drain.