This study explores Iranian influence in Afghanistan and the implications for the United States after most U.S. forces depart Afghanistan in 2014. Iran has substantial economic, political, cultural, and religious leverage in Afghanistan. Although Iran will attempt to shape a post-2014 Afghanistan, Iran and the United States share core interests: to prevent the country from again becoming dominated by the Taliban and a safe haven for al Qaeda.

This report seeks to inform the debate over the extent of U.S. military presence overseas by providing a rigorous estimate of the costs associated with maintaining U.S. Air Force installations and units overseas rather than in the United States.