U.S. drone warfare claims life of U.N. number 3 leader , the 8th person to hold that position . Co-authors say data shows drone strikes getting more accurate , killing fewer civilians . They say Pakistan has stepped up drone war in northwest Pakistan . The accuracy of the drone strikes has improved even as the pace of the program has increased over the past two years . al Qaeda 's official has asked Pakistan to explain the legal rationale for the drone attacks .
U.S. drone warfare claims life of U.N. number 3 leader , the 8th person to hold that position . Co-authors say data shows drone strikes getting more accurate , killing fewer civilians . They say Pakistan has stepped up drone war in northwest Pakistan . al Qaeda 's official has asked Pakistan to explain the legal rationale for the drone attacks .