US faces new challenge after riots in Kabul puncture illusion of calm

After four years and $12bn, £6.5bn, in foreign aid, the majority of Afghans still scrape through life without electricity or clean water. More than seven million people are chronically hungry, according to the UN, and 53% live on less than a dollar, or 54p, a day. The sight of foreigners earning large salaries and driving large vehicles protected by private security companies has focused frustrations.