Winning a war is a confusing experience for an insurgent or terrorist group. The sudden crush of responsibility that follows taking over a country calls for a very different skill set from that required while trying to overthrow a government.

Not only are you now expected to deliver on a whole suite of basic public services, but you also have to provide security - the very thing you used to undermine. This can come in the form of defending borders, stopping criminality, or fighting terrorist groups; the last, ironically, is a growing headache for the Taliban, now that it is the ruler of Afghanistan.