Convergent Flexibility: How International Law Keeps Pace with Technological Change

If change is the only constant, how does the law keep pace with technology? Without a centralized judiciary, international law should be especially susceptible to disruption, yet it can be remarkably resilient in practice. I argue that efforts to minimize legal ambiguity, long seen as integral to compliance, can hinder its application to new technologies. Drawing on first principles from psycholinguistics, my theory differentiates between what I call convergent and divergent forms of flexibility. Unlike divergent flexibility, which gives rise to contestation, convergent flexibility tends to promote consensus, even when (1) technology is unprecedented and (2) regulatory interests sharply diverge. To test the theory, 450 450 $450$ trained legal professionals were commissioned to take part in a randomized controlled trial (RCT) that varied technological novelty, legal precision, and political incentives. Participants collectively contributed 280,000 words over 10,000 hours in defense of their professional legal opinions, offering a novel (agent-subjective) measure of compliance. To establish external validity, the experiment is complemented with research into the legal impact of two breakthrough chemical weapons technologies: “super tear gas” and novichok. The findings contribute a general theoretical framework for understanding when and why emerging technologies are legally disruptive.