Maybe drones will make human soldiers unacceptable in the future.

“It occurred to me that if I could invent a machine - a gun - which could by its rapidity of fire, enable one man to do as much battle duty as a hundred, that it would, to a large extent supersede the necessity of large armies, and consequently, exposure to battle and disease [would] be greatly diminished.” ― Richard Jordan Gatling, 1877

If only wars would end when all the soldiers on one side were dead.

If the people fought before they'll keep fighting, even after their robots are gone.

They will certainly make human soldiers unviable. (I draw mostly dystopian conclusions from that prediction.)