The New America Foundation has a report out which seeks to tally the number of deaths from US drone attacks within Pakistan. According to their findings, one in every three deaths of that sort, or somewhere between 250 and 320, were civilians.
The methodology of the report excludes all but the most credible of news organizations’ reports on battle deaths, so even still this estimate is probably on the conservative side. And as Spencer Ackerman at the Washington Independent points out, there is a problem with determining who exactly is a “militant” and who is not. The line between combatant and civilian is blurry in a place like Pakistan.
If you were playing a video game and for every 2 bad guys you killed, you killed one innocent, you wouldn’t get very far in the game. So I’m going to propose that we adopt some kind of video game-based rule for a war strategy’s efficacy. If you couldn’t pull it off in 1943 (the game, see below) then it definitely shouldn’t be done in real life to real people.