International Humanitarian Law and International Human Rights Law


The Law of Consent-Based Interventions

Just Security (Oct. 13, 2016) (with Sarah Weiner)

Consent is Not Enough: Respecting the Intensity Threshold in Transnational Conflict

165 U. Pa. L. Rev. 1 (2016) (with Oona A. Hathaway, Daniel Hessel, Julia Shu, and Sarah Weiner)

It is widely accepted that a state cannot treat a conflict with an organized non-state actor as an armed conflict until the violence crosses a minimum threshold of intensity. But can a host state consent to a use of force that would be illegal for the host state to use itself? And can an intervening state always presume that host state consent is valid?

This article argues that host state consent is limited and that intervening states cannot treat consent as a blank check. Accordingly, even in consent-based interventions, the logic and foundational norms of the international legal order require both the consent-giving and consent-receiving states to independently evaluate which legal regime governs—which will often turn on whether the intensity threshold has been met. If a non-international armed conflict exists, the intervening state may act pursuant to international humanitarian law; if not, its lawful actions are limited by its own and the host state’s human rights obligations.

Which Law Governs During Armed Conflict? The Relationship Between International Humanitarian Law and Human Rights Law

96 Minn. L. Rev. 1883 (2012) (with Oona A. Hathway, Philip Levitz, Haley Nix, William Perdue, Chelsea Purvis, and Julia Spiegel)

Notwithstanding increasing state interest in the issue, no one has yet put forward a coherent legal definition of autonomy in weapon systems, resulting in a confusing conflation of legal, ethical, policy, and political arguments. This article proposes that an “autonomous weapon system” be defined as “a weapon system that, based on conclusions derived from gathered information and preprogrammed constraints, is capable of independently selecting and engaging targets.” Contrary to the general consensus, such systems are not weapons of the future: they exist and are in use today.

This fact has two main implications: it undermines almost all legal arguments for a ban, as they are based on the false assumption that such weaponry could never be lawfully employed; and it significantly reduces the likelihood that a successful ban will be negotiated, as states will be reluctant to voluntarily relinquish otherwise lawful and uniquely effective weaponry. Accordingly, this article concludes with a discussion of how best to create successful international regulations.

International Law and Targeted Killings in Pakistan

White Paper submitted to the Office of the Legal Advisor, U.S. Dept. of State (2010) (with Brian Finucane and Oona A. Hathaway)

This report evaluates the lawfulness, under international law, of U.S. use of unmanned aerial vehicles to target non-state actors in Pakistan.


Dr. Crootof also often writes on international humanitarian law and international human rights law in the context of discussing new weapons technologies.