León Castellanos-Jankiewicz is senior researcher at the Asser Institute for International and European Law in The Hague and the University of Amsterdam Faculty of Law. He regularly advises governments on matters of international law, and has extensive experience working in projects involving interdisciplinary research, multistakeholder engagement and advocacy.

His research covers three broad areas. First, he is interested in arms trade and weapons transfer policy, in particular human rights safeguards, export controls, corporate accountability and due diligence. Second, he looks at the governance of global public goods through private law, including strategic litigation and supply chain resilience. Finally, he conducts research on legal history, focusing on the intersection of ideas between public and private international law.

His academic work has been published in prominent venues, including the American Journal of International Law Unbound, the European Journal of International Law, and the Journal of the History of International Law. He frequently writes for print and online publications, including El País, NRC and Just Security and is a listed expert in the Forum on the Arms Trade. He sits on the Advisory Committee of Global Action on Gun Violence and is a regular commentator in the media.

Previously, he was Max Weber Postdoctoral Fellow at the European University Institute, and held visiting positions at Harvard Law School and the Lauterpacht Centre for International Law, University of Cambridge. He holds a PhD in International Law from the Geneva Graduate Institute.

For press inquiries and other engagements you may contact him at L.castellanos@asser.nl.