The recent surge in the use of robotic and remote weapons systems represents an unprecedented shift in the means and methods of waging war in the 21st century. Enabled by rapid technological advances in computing and robotics, these methods have gained popularity at a time of changing military tactics and strategies, governmental policy, and growing political pressure to avert military casualties. The development of appropriate legal controls has however lagged behind. Combining autonomous artificial decision-making with the ability to deliver lethal or debilitating force, robotic and remote weapons systems fundamentally challenge orthodox moral and legal understandings of responsibility in the conduct of armed hostilities. Specialising in dirty, dull, and dangerous tasks, robotic or remote weapon systems may become the paragon peacekeeper. Willingly exposed to danger, rationally calculating, capable of exercising disproportionate restraint, and non-lethally equipped, the removal of risk to the intervening third-party may justify the shift from the paradigm of armed conflict to that of police action. At the same time, models of policing are becoming militarised, giving rise to the possibility that robotic and remote weapons systems may permeate civilian society far from situations of armed conflict. This pioneering study seeks to advance legal understanding and to inform appropriate responses. At its core is an analysis of key questions: first, it asks whether it is appropriate to attribute responsibility to a machine due to a lack of moral culpability and because of the absence of possible deterrent or punishment mechanisms? Second, does the autonomy of the weapons system either neutralise the responsibility of, or conversely scapegoat, the human combatant or commander for the deployment of such weapons systems? Impunity for the use of robotic and remote weapons systems will coalesce into an impenetrable lacuna situated beyond the reaches of contemporary legal responsibility that is capable of jeopardising the humanitarian core to which both jus ad bellum and jus in bello gravitate. The book also considers the impact upon international humanitarian and human rights law. The book is aimed at policy-makers, government officials, legal practitioners, military professionals, academics, researchers, campaigners, advanced students and journalists.