WASHINGTON – The United States on Friday lifted the lid on one of the most controversial tactics of President Barack Obama's secretive counterterrorism campaign, detailing for the first time the number killed in airstrikes in countries like Pakistan and Libya. The White House also released an executive order outlining the steps that should be taken to reduce civilian casualties in America's battle against violent extremism. In a much-anticipated report, National Intelligence Director James Clapper provided fatality estimates for the 473 strikes between 2009 and 2015 that were conducted outside America's principal war zones in Iraq, Syria and Afghanistan. He said between 64 and 116 civilians were killed, and up to 2,581 combatants. Such attacks are typically conducted via drones, though manned warplanes and missiles have also been used.