The Rev. Dr. Paul F.M. Zahl makes it:
Our use of drones are out of “proportion” because it uses the most advanced technology in the world to assassinate people who can basically only throw the equivalent of sticks and stones back at you. Moreover, it gives these people no chance to surrender. It is like capital punishment without an arrest, a charge, a trial, or a right of appeal.
Our use of drones is not humane, because it totally objectifies the enemy by making them into a picture on a screen. There is not the faintest possibility, in the conduct of drone warfare by means of remote control, that you can regard the enemy as a fellow human citizen of the planet.