* No soldiers of the side deploying armed drones need to be in danger.
* Robots do not act cruelly unless specifically instructed. Humans do have a pretty bad record of unnecessary cruelty due to racism, boredom, intoxication etc.
* If you log all descision making processes, you can justify each action taken. It's like bodycams for police officers. If you'd make all logs public after the war it would be possible to identify war crimes and who gave the order (unlike now).
* Nothing requires a machine to use lethal force all the time. Systems which have the primary purpose of capturing combattants can be considered when there's no risk of losing one of your own soldiers.
* Your robots priority doesn't have to be self-preservation (unlike a human soldier). When in doubt, don't shoot and analyze the situation.
All in all, if the military would use these autonomous killing machines with the intent of minimizing covilian casualties, would this not be an improvement over the current state of warfare? Of course it won't make war per se less likely, but not using these machines doesn't either. So why not use them?