You need boots on the ground if you want to control a population especially if you are worried that you might be labeled a war criminal. If just want to control an area and don't care about international laws you could inflict enough damage to either kill or force out a significant percentage of the population. You only have to look at America's western expansion to see how it would work.
Regardless, DARPA and the Pentagon have a real life remote controlled autonomous tank as opposed to a simulation. Crusher as the Pentagon calls it.
And the LS3 which is best described as a dog like robot
goes into field testing this year.