Non-Binding Norms in the Law of Armed Conflict

by | Feb 3, 2022

Non-Binding Norms and LOAC

In the aftermath of the U.S. invasion of Afghanistan, Bush administration appointees criticized the Geneva Conventions as being, among other things, obsolete and out of date. Indeed, one of the consistent criticisms of the law of armed conflict (LOAC) has been its historical (perhaps even historic) inability to effectively predict new developments and proactively develop laws to deal with new practices and developments. A criticism almost as old as LOAC itself is that it is always fighting the last war.

There is some truth to this; LOAC treaties have, for the most part, been reactive, responding to the conduct of the most recent conflict, rather than predicting conduct yet to come. However, recent years have seen a trend toward reversing, or at least tempering, this reactive quality. States, civil society organizations, and experts, usually acting in small groups, have drafted and published manuals of instruction on new and emergent means and methods of warfare that are either entirely unregulated or notably underregulated under existing law. Rather than waiting for the international community to adopt new treaties, these small groups of interested stakeholders have instead engaged in norm development, in the form of non-binding instruments. These non-binding instruments have been designed as either “best practice” guidelines, or (re)statements of applicable law. They are not treaties and are not intended to be binding.

Non-Binding Instruments

This development in LOAC is not new to international law, nor even to LOAC itself. Non-binding instruments have been part of LOAC lawmaking for decades, with States and even non-State actors adopting non-binding instruments, in the form of codes of conduct, manuals of instruction, or other draft or non-binding instruments. For example, in 1880, the Institute of International Law published its Manual on the Laws of War on Land. As its preamble made clear, the Oxford Manual, as it came to be known, was not intended as “an international treaty, which might perhaps be premature or at least very difficult to obtain.” The Institute produced it nonetheless to fulfill “a duty in offering to the governments a ‘Manual’ suitable as the basis for national legislation in each State, and in accord with both the progress of juridical science and the needs of civilized armies.”

Non-binding provisions have even been included in “hard law” LOAC treaties. For instance, Common Article 3 in the 1949 Geneva Conventions includes a provision that encourages parties to a non-international armed conflict to “further endeavour to bring into force, by means of special agreements, all or part of the other provisions of the present Convention.”  The 1977 Additional Protocol II to the 1949 Geneva Conventions includes a further statement of recommended practice in Article 6 that encourages extensions of amnesty to non-State participants in non-international armed conflicts.

There are now a considerable number of non-binding instruments that are part of the landscape of LOAC, from the well-respected and widely embraced San Remo Naval Manual of 1994, to newer instruments like the Leuven Manual on the International Law Applicable to Peace Operations. In many respects, these instruments are beneficial for those who engage with LOAC—they are (usually) measured, thoughtful, well-researched statements of the law as it applies to new and complex situations.

By drawing on the expertise of a small group of contributors, these instruments can be debated and drafted in a timely manner, arguably quicker than if these issues were left to the international community of 196 States to resolve. Additionally, because these instruments are not subject to debate at an international conference of States, the provisions are not subject to the usual revisions, reservations, and dilutions that come with attempting to reach consensus among numerous States. Non-binding instruments have the potential to be dynamic, prompt, and responsive measures to address pressing issues in armed conflict situations.

Concerns with Non-Binding Instruments

Nonetheless, these non-binding instruments raise some issues regarding their substance and procedure. Concerns about legitimacy are obvious; these documents are often debated and drafted by relatively few experts, sometimes as few as thirty. Keeping the group of experts to a small number can make the drafting process more manageable, but equally, it might mean that only a limited number of perspectives are represented—especially if the experts represent only select legal, geographical, social-cultural, or political backgrounds.

In practice, experts involved in one instrument’s creation have often been involved in drafting other instruments. While resorting to the wealth of expertise offered by these individuals is obviously helpful, it equally might mean that only certain doctrinal or theoretical positions are reinforced and perpetuated. And while attempts are clearly made to ensure that the final instrument reflects lex lata, some instruments have been closer to lex ferenda (such as with the ICRC Expert Guidance on Direct Participation in Hostilities).

Connected to concerns about the legitimacy of these instruments are issues regarding their legality. Are these instruments treated as legal documents in any way, and if so, what implications arise? Do they have any authority to claim themselves as being instructive, or to hope to influence behavior? Do they deserve any deference or respect as (semi)authoritative statements despite their non-binding status?

Finally, it is useful to examine whether these instruments are effective. How have they been received by States and other participants in armed conflicts? Do they shape or influence practice in conflicts? If these instruments are effective, and are followed in practice, the questions regarding their legitimacy and legality become even more pressing.

New Research

I explore these questions in detail in my new monograph, Non-Binding Norms in International Humanitarian Law: Efficacy, Legitimacy, and Legality (Oxford University Press 2021). While the role of non-binding norms and soft law in international law has been the focus of considerable debate for some years now, there is insufficient attention paid to the growing centrality of non-binding norms in LOAC. The result of several years of research on the topic, the book explores whether these instruments are being used in practice, and what the turn to the non-binding form in LOAC tells us about lawmaking in international law, and in LOAC more specifically. The research demonstrates that non-binding norms can be beneficial additions to LOAC theory and practice, but to be maximally effective, they must be mindful of who participates in their creation and how they approach their subject matter.


Emily Crawford is an Associate Professor at the University of Sydney Law School and a co-editor of the Journal of International Humanitarian Studies.