“State Opinio Juris and International Humanitarian Law Pluralism” by Michael N. Schmitt and Sean Watts

By Kenneth Anderson
Wednesday, June 10, 2015, 6:56 AM

Mike Schmitt is well-known to many, probably most, regular readers of Lawfare—eminent and prolific scholar of the law of armed conflict (or international humanitarian law); driving force behind the Tallinn Manual on the application of LOAC to issues of cyberwar; and the rare scholar of LOAC who is navigates fluidly between US and European scholarly LOAC communities (with academic appointments in the US and the UK), as well as between military views of LOAC and those of other key players, such as the International Committee of the Red Cross. Under his leadership as Executive Director of the Stockton Center for the Study of International Law and Stockton Professor at the US Naval War College, conferences at the NWC as well as the NWC’s venerable academic journal International Law Studies have flourished. Sean Watts is probably less well-known to Lawfare readers; a former US Army JAG, he is a professor at Creighton University School of Law, where he teaches criminal law as well as LOAC-related topics, and serves as an Army Reserve instructor on LOAC issues at the USMA at West Point, and other places, among his many activities. I first met Sean when he was still an active duty JAG officer, and was immediately struck by his fluid grasp of both detailed operational law of war issues as well as the larger scholarly questions standing behind those issues.

Given the eminence and expertise these two scholars bring to the table, I was interested and pleased to see the SSRN notice of their new paper, “State Opinio Juris and International Humanitarian Law Pluralism,” which (apparently drawing together several different articles in a new way) appears in 91 International Law Studies 171 (2015) and 50 Texas International Law Journal (2015).

As Larry Solum of Legal Theory Blog might say, “highly recommended.”

The inquiry of the paper fits into a broader question of “authority” to make, declare, or interpret international law, at a point in time when (as the title of the Schmitt-Watts paper suggests with respect to IHL/LOAC), pluralism as to “who,” in actual fact, raises their voices to pronounce “the law” has become peculiarly lopsided. As their paper suggests (quite accurately in my view), states and particularly militarily significant states, on the one hand, have become increasingly reticent about stating their views, whether as “formal” opinio juris with respect to customary international law, or even simply as a public statement of their actual state practice, an assessment of its basis in international law, and an assertion of its legality, short of a declaration of formal opinio juris.

On the other hand, non-state individuals and organizations, whether scholars or advocacy organizations, have strongly moved into the “declaratory” space, offering no end of “authoritative”-sounding declarations, reports, briefs to all sorts of international institutions, and scholarship. This is partly because (in my personal experience, anyway), they genuinely believe their own views; partly because they believe that they are “stakeholders” in the system of making, declaring, and interpreting LOAC/IHL; and partly because they have learned over several decades (consonant with the incentives created by the general withdrawal of states from this space) that given the lack of knowledge of the broader non-lawyer international community (including journalists and the broader public), one can create a conversation and controversy over a topic that never existed before simply by confident, unshakeable assertion of one’s expertise and authority.

With respect to the US government and its national security agencies, Schmitt and Watts offer an eloquent call for states, and particularly the United States, to speak up both with regards to their emerging state practice and formal opinio juris. It is in line, of course, with similar calls from many quarters, including many commentators here at Lawfare. There are further issues as to how this call for acknowledged state practice and formal opinio juris bears, for example, on the series of national security law speeches given by Obama administration officials and senior lawyers over the last several years (and, mirabile dictu, topic of a new book by Ken and Ben, Speaking the Law - ed.) But this article addresses state practice and opinio juris in a way that draws the analysis up to encompass IHL/LOAC as a whole, and while it has particular salience for the US government, it is an argument that extends more broadly to states and particularly militarily significant states.

SSRN Abstract

International humanitarian law has developed through a pluralistic process. Its history reveals a pattern of rough proportionality between State opinio juris and non-State expressions of law. These diverse sources have maintained a respectable yet realistic balance between humanity and military necessity. However, present IHL dialogue presents a stark contrast to the vibrant and pluralistic exchanges of the past. The substantive input of non-State actors such as non-governmental organizations, tribunals, and scholars far outpaces the work of States. Parity of input, especially in quantitative terms, is surely too much to demand and surely not necessary given the special status of State opinio juris. However, States’ legal agencies and agents should be equipped, organized, and re-empowered to participate actively in the interpretation and development of IHL. This Article, extracted from a larger work, argues that reinvigorating opinio juris would reestablish the pluralistic IHL dialogue that formerly tested, updated, and enriched the balance between military necessity and humanity. (pdf 46 pp.)