THE ISSUE: The Islamic State group seized swaths of land in Iraq and expanded its territory in Syria in a dramatic blitz in 2014, taking advantage of unrest in both countries. The militant group slaughtered civilians in its march to try to establish a radical caliphate, and has spawned a string of deadly attacks across Europe, the Middle East and the United States.
In response, the U.S. and a coalition of allies launched a sustained campaign of airstrikes in Iraq and Syria in 2014, and have been training, advising and supporting local forces in both countries. Recently, the U.S. added Libya to its airstrike targets to root out extremists at the request of the Libyan government. While still a potent force, IS militants have lost much of the territory they overran. Meantime. they've stepped up attempts to inspire followers abroad to strike on their own, with some devastating results.