evidence: Since 2001, the United States has spent $2.26 trillion in Afghanistan, the Costs of War Project at Brown University calculates – an investment that has yielded a chaotic, humiliating end to America’s longest war. [...] Since 2001, the US has appropriated more than $144bn to Afghan reconstruction. Much of that money went to private contractors and NGOs the US government tasked with implementing programmes and projects to build Afghanistan’s security forces, improve governance, aid economic and social development and combat illicit drugs. The most critical failure of those reconstruction efforts – and the most expensive – was the $88.3bn spent training and equipping the Afghan army from May 2002 to March this year.