In the aftermath of the German U-boat campaign in the First World War, many in Europe and the United States argued that submarines were immoral and should be outlawed. The British Admiralty supported this view, and as Blair has described, even offered to abolish their submarine force if other nations followed suit. While British proposals to ban submarines in 1922 and 1930 were defeated, restrictions on their use where imposed that mandated that submarines could not attack a ship until such ships crews and passengers were placed in safety. This reaction to the development of a new means of war is illustrative of the type of ethical and legal challenges that must be addressed as military organizations adopt greater human-machine integration. This article is the final of three that examines the key aspects of human-machine teaming.