Foreign policy, development, and humanitarian aid have had little coverage in the US presidential campaign. However, the issues will still be in the in-tray of Donald J. Trump come January. Here are some of the most pressing: The war in Afghanistan Trump will inherit the longest war the US has ever fought – in Afghanistan. The US invaded in 2001, backing local forces to overthrow the Taliban, and still maintains about 10,000 troops there. Obama has promised to end the war, but Afghanistan’s military has not been able to hold off an onslaught by the Taliban and other militant groups on its own, and the government has often been fragile almost to the point of collapse.