There are many people, decisions and technologies involved in the process leading to the use of force in military operations. Each of these touch points is a locus for applying — or failing to apply — accountability when things go wrong. The “accountability surface” is a new term of art to characterize the degree to which humans involved in the use of force can be held accountable for undue harm in warfare. As a metaphor, the accountability surface insists upon a crucial question regarding the use of military autonomous and automating technologies: Will the use of this technology expand or contract the degree to which anyone in the organization will be held accountable for any harms resulting from any process in which it plays a role? Automating technologies have the potential to significantly diminish the accountability surface of militaries that use them.