Monica Hakimi (University of Michigan) joins us to talk about flaws of international legal positivism, interplay between formal and informal law, and customary international law. Publications referred to in the episode: Jutta Brunnée and Stephen J. Toope, Legitimacy and Legality in International Law: An Interactional Account (New York: Cambridge University Press, 2010). Monica Hakimi, ‘The Jus ad Bellum’s Regulatory Form’, American Journal of International Law 112, no. 2 (2018): 151–90. Monica Hakimi, ‘Making Sense of Customary International Law’, Michigan Law Review 118, no. 8 (2020): 1487–1538. Don Herzog, Sovereignty, RIP (New Heaven: Yale University Press, 2020).