Taliban fighters pose with weapons at an undisclosed location in Afghanistan, August 19, 2009. (Reuters) Short Url The US military last week handed control of the vast Bagram Air Base to the Afghan government. US troops and their NATO allies are now on track to leave Afghanistan by mid-July, well ahead of US President Joe Biden’s Sept. 11 withdrawal deadline. According to a new analysis by researchers at Brown University, America’s two-decade war in Afghanistan cost it nearly $2.3 trillion. Now, Afghanistan’s regional neighbors — Pakistan, Iran, China, India and the Central Asian countries — are wondering just how much it will cost them to maintain security after the US is gone.