Opponents couldn't make political hay out of former U.S. Vice President Dick Cheney's withholding (if he did) from congressional scrutiny secret CIA programs to assassinate high-ranking al Qaeda operatives, if people had no qualms about targeted killing. But they do. Governments can bomb faceless troops of enemy conscripts with impunity, but are questioned closely about bombing photographable individuals. Numbers numb; identity humanizes. That's the general rule.