"Completely replace" would mean "there is nobody on the ground, everything is remote". There would still be people remotely overseeing operations. As for how widespread that would be, let us say that this should apply to at least one nation with real combat experience (size does not matter).
Can you operationalize the resolution criteria? “Completely replace” is a bit vague.
Does the question resolve once ~virtually all (>99%) of direct operation of military equipment is autonomous or manned remotely? If humans are deployed to combat zones, but they don’t engage in direct combat (in favor of command and control or something), does the question resolve? What if there are still traditionally armed infantry units stationed in combat zones, but they’re used very rarely instead of drones?
What about if there are still people on naval vessels like aircraft carriers, but all weapons systems are automatic?
Does this resolve based on the capabilities of at least one nation, or does it have to be common among many nations? Do small nations with small militaries count? If a nation has a ~completely automated military but isn’t using it in a time of peace, does the question resolve? What about if a nation clearly has the capability not to use soldiers but chooses to use them anyway?
@AdamK "Completely replace" would mean "there is nobody on the ground, everything is remote". There would still be people remotely overseeing operations. As for how widespread that would be, let us say that this should apply to at least one nation with real combat experience (size does not matter).