Two Decades After 9/11, Militants Have Only Multiplied

FILE -- Destruction along the front lines in the fight to retake Mosul, Iraq, from the Islamic State, July 15, 2017. Nearly four times as many Sunni Islamic militants are operating around the world today as on Sept. 11, 2001, despite nearly two decades of American-led campaigns to combat Al Qaeda and the Islamic State, a new independent study concludes. (Ivor Prickett/The New York Times)