Gradually, perhaps imperceptibly, automated systems will function so much more efficiently that humans will become mere bystanders. The soldier will become the slowest element in an engagement, or will simply become irrelevant. Adherence to the rules of war will become less relevant as well. A separate set of ethical questions are raised by the technologies of human "enhancement" and augmentation, which include improving physical strength, stamina and pain tolerance, as well as using neurological implants and stimulation to restore brain function and enhance learning. Can soldiers under the influence of behavior-modifying drugs or electronics be held to account for their actions?