With the progress of machine learning, facial recognition, algorithms etc, you'll likely see a point where machines are actually able to make these choices better than a person, they certainly don't feel pressure and make hasty decisions based on their own survival.
Certainly lots to think about on this subject! But as someone who has spent a lot of time in warzones as well, humans can make some pretty bad decisions alone sometime.
My main problem is the lack of consequences. Here in the UK, when a soldier was killed it made the news, and everyone in theatre hears about it. This has an effect of forcing the public and politicians to reassess the war and think about whether or not it's a good idea. If you make war so remote, it allows people to have cognitive dissonance.
I agree, one would hope, that in the future... if we are advanced enough to have thinking, killer robots it may just be time to be civil to one and other and work for peaceful solutions.