WBEZ brings you fact-based news and information. Sign up for our newsletters to stay up to date on the stories that matter.This year, there have been an estimated twenty-one airstrikes in Yemen—the majority of which have been drone strikes. As the U.S. attempts to battle terrorist groups such as al-Qaeda and Al Qaeda in the Arabian Peninsula, many have raised questions about the efficacy of drones strikes as part of a larger counter-terrorism strategy. Micah Zenko, the Douglas Dillon fellow at the Council on Foreign Relations, evaluates how effective the U.S. counter-terrorism strategy is. (Photo: AP Images).