By J.P. LAWRENCE AND ZUBAIR BABAKARKHAIL | STARS AND STRIPES Published: April 16, 2021 KABUL, Afghanistan Over the last 20 years, Bagram and other towns in Afghanistan became dependent on the sprawling U.S. military bases nearby for their economy and their security. In a few months, they may not have much of either. The flow of discarded goods from Bagram Airfield slowed to a trickle last year when U.S. troop levels in the country went from 12,000 down to about 2,500. What’s left of that commerce is expected to run out by Sept. 11, the date set for all U.S. and NATO troops to have left the country.