Autonomous Weapon Systems and the Limits of Analogy

28 Pages Posted: 13 Aug 2016 Last revised: 10 Feb 2018

Rebecca Crootof

Yale University - Yale Information Society Project; Yale University - Law School

Date Written: January 9, 2018


Most imagine autonomous weapon systems as either more independent versions of weapons already in use or as some kind of humanoid robotic soldier. In many ways, these analogies are useful. Analogies and allusions to popular culture make this new kind of weaponry accessible, identify potential dangers, and augment desired narratives. Most importantly from a legal perspective, analogical reasoning helps stretch existing law to cover developing technologies and thereby avoid law-free zones.

But neither these nor other analogies based on unconventional entities that participate in armed conflict—namely, child soldiers and animal combatants — are apt for autonomous weapon systems. All of these potential analogies misrepresent legally-salient traits: conceiving of them as weapons minimizes some autonomous weapon systems’ capability for independent and self-determined action, while the combatant, child soldier, and animal combatant comparisons overemphasize it. Furthermore, all of these analogies limit our ability to think imaginatively about this technology and anticipate how new kinds of autonomous weapon systems might develop, impeding our ability to properly regulate them.

As is often the case when law by analogy fails, what is needed is new law. The sooner we escape the confines of these insufficient analogies, the sooner we can create comprehensive and effective regulations for this challenging new technology.

Keywords: autonomous weapon systems, international humanitarian law, law of armed conflict, analogy, weapons, combatants, child soldiers, animals, killer robot

Suggested Citation

Crootof, Rebecca, Autonomous Weapon Systems and the Limits of Analogy (January 9, 2018). Available at SSRN: or

Rebecca Crootof (Contact Author)

Yale University - Yale Information Society Project ( email )

127 Wall Street
New Haven, CT 06511
United States

Yale University - Law School ( email )

P.O. Box 208215
New Haven, CT 06520-8215
United States

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