Fortunately, this is a case where the least convenient possible world is quite unlike the real world, because modern wars are fought less with infantry and more with money and technology. As technology advances, military robots get cheaper, and larger portions of the military move to greater distances from the battlefield. If current trends continue, wars will be fought entirely between machines, until one side runs out of robots and is forced to surrender (or else fight man-vs-machine, which, in spite of what happens in movies, is probably fruitless suicide).