Lets say in the near future our research into automated drones and remote controlled weapons has grown better. We have reached the point where putting people in the weapons is counterproductive, it requires engineering a location where people can be protected, adds an extra avenue of attack, and in case of flying machines limits the machine by the Gforce the humans can maintain etc etc.
Thus new weapons tend to all be either 100% automated (I am not talking hard thinking AI, I'm talking like the smart missiles of today, soft AI with enough programing to probably blow up the thing that is shot at) or remote controlled by human pilots. Limits to our AI ability means remote control of more complex weapons, like fighter jets, is still required. For now assume that fighter jets and tanks still exist (yes I know were likely move more and more to only using missiles, but in the world I'm most interested in I have used hand waves to keep human flown fighters because that's the story I want to tell)
Humans will have to be relatively close ('relatively' can still be quite a distance, no risk of stray bomb blowing you up) to these weapons due to the limits of light speed communication and the harm that even minor latency can cause. This could make a tempting tactic to attack the pilots of the machines, via missiles or even suicide bomber approach. Hit one place with a even a half dozen remote pilots you can knock out a huge number of expensive weapons...
This trend in weapons in some ways makes warfare more about economic power then human capital. There is no point in infantry or grunts, and while pilots, and the massive support team for weapons, we have still gotten to the point where it's much easier to train up new pilots and support staff then build new fighters, and thus whoever can build better weapons or build weapons faster has the advantage, not whoever has the most people willing to die for their country.
At the same time the bigger-badder conventional weapons mean that if a country decides to turn these weapons on civilians they are absurdly lethal. Even if they aren't weapons of mass destruction...well Napalm killed more Japanese civilians then the nukes in WW2 ultimately. With weapons traveling so fast it's become harder and harder to protect civilian, or economic, structures; it's not really possible to hold the line at some point away from civilians. It's possible for even a few weaker fighters/bomber hybrids to be quite devastating if they choose to attack civilians.
Recognizing both the lethality, and impossibility to prevent, conventional weapons turned against civilians or even infrastructure, and the fact that battles have focused more and more ultimately on infrastructure and who can knock out the others weapons rather then attrition of personnel, some have decided to try to encourage wars to be a more economic battle. They write a pact, similar to the Geneva convention, designed to allow these weapons to attack and destroy each other without killing humans. The conventions include not killing the remote pilots of weapons (capture is allowed), and setting up a system where a territory which has a few weapons over it without any competing sides fighters nearby is considered captured and should cooperate with the captures so long as they abide by the conventions rules etc.
How far can such a convention go while having any hope of being respected by larger first world nations (the smaller nations won't sign or respect it, gurella warfare and terrorism being the only viable ways of fighting for them, so I'm focused only on the big factions for this question). Some kind of casualties will have to be allowed sadly, but how much will the larger nations agree to focus on a system where humans are off limits?
My question is, would it be reasonable to expect a geneva convention style agreement to avoid attacking human pilots of these weapons? Or more generally to avoid attacking humans with your big-expensive-blow-things-up weapons so long as they comply with specific rules, to basically make wars an economic battle to see who can blow up the other's sides big-fancy-weapons first with limited human casualties?
I'm trying to think real world, and real world will have humans dieing no matter what in a war of course. So perhaps the better question is what sort of convention could be written that is likely to actually be respected by the bigger powers (I'm looking at the big first world nations, smaller nations with fewer expensive weapons would be more likely to use gurella warfare and terrorism and basically ignore the convention obviously).