According to him, the drone is not just morally acceptable but "morally obligatory." If you wish to kill in conformity with moral law, you have to use a drone. His thesis is based on what he calls the "principle of unnecessary risk," according to which it is "wrong to command someone to take on unnecessary potentially lethal risk." His reasoning runs as follows: "I argue that we have a duty to protect an agent engaged in a justified act from harm to the greatest extent possible, so long as that protection does not interfere with the agent's ability to act justly. UAVs afford precisely such protection. Therefore, we are obligated to employ UAV weapon systems if it can be shown that their use does not significantly reduce a warfighter's operational capacity."

Grégoire Chamayou, A Theory of the Drone, loc. 455