How Did We Not See This Coming?

Shane Harris explains why the US government was caught off guard by Iraq’s sudden implosion:

The CIA maintains a presence at the U.S. Embassy in Baghdad, but the agency has largely stopped running networks of spies inside the country since U.S. forces left Iraq in December 2011, current and former U.S. officials said. That’s in part because the military’s secretive Joint Special Operations Command had actually taken the lead on hunting down Iraq’s militants. With the JSOC commandos gone, the intelligence agencies have been forced to try to track groups like ISIS through satellite imagery and communications intercepts — methods that have proven practically useless because the militants relay messages using human couriers, rather than phone and email conversations, and move around in such small groups that they easily blend into the civilian population.