The Updated GCIII Commentary: A Flawed Methodology?

by | Feb 3, 2021

GCIII Commentary. East Timor 2006. ICRC – Roland Bigler


In June of 2020, as part of its ongoing multi-year effort, the International Committee of the Red Cross (ICRC) launched its updated Commentary on the Third Geneva Convention of 1949. The Commentary analyzes how practice in the application and interpretation of the Third Geneva Convention has evolved in the past decades. According to the ICRC, it also provides a fresh interpretation of the Convention, taking into consideration legal and technological developments that have occurred since the publication of Pictet’s Commentary on the Third Geneva Convention over sixty years ago.

In December 2020, Professor Sean Watts discussed certain aspects of the updated Commentary, such as subsequent practice, textual integrity, and ambiguity. I concur with his praise that the new commentary is a “remarkable feat of scholarship worthy of academic attention” as well as his caution that it is a “fraught source for the military, diplomatic, and judicial practitioners” who have to interpret and implement the Convention on behalf of a State Party.

This post will expand on one aspect of Professor Watts’s post by focusing on the methodology used by the ICRC in compiling the Commentary. Specifically, four aspects of the Commentary depart from established principles of treaty interpretation: consideration of the object and purpose; insufficient weight to State practice; reliance on subsequent treaties; and mixing the law as it is with the law as it should be.

ICRC Methodology

In drafting the Commentary, the ICRC acknowledged that the Third Geneva Convention should be interpreted in accordance with Article 31(1) of the 1969 Vienna Convention on the Law of Treaties “in good faith in accordance with the ordinary meaning to be given to the terms of the treaty in their context and in light of its object and purpose” (para 75).

Article 31(2) of the Vienna Convention indicates treaty context comprises not only the text of the treaty, but also its preamble and annexes. Additionally, the Commentary, pursuant to Article 31(3), considers: subsequent agreements between the Parties regarding the interpretation of the treaty or the application of its provisions; any subsequent practice in the application of the treaty which establishes the agreement of the Parties regarding its interpretation; and, any relevant rules of international law applicable in the relations between the Parties.

The ICRC specifically mentions international criminal law, international human rights law, the Additional Protocols to the Geneva Conventions, customary international law, and the law of State responsibility as “relevant rules” it considered.

The question then is what do these considerations really mean and did the ICRC, in compiling this revised Commentary, properly apply these accepted precepts of treaty interpretation?

The Vienna Convention on the Law of Treaties

The Vienna Convention provides the general rules for treaty interpretation, which have been recognized as customary international law by international tribunals and States, including the United States.[1]

Article 31 is entitled the “general rule” of interpretation. The singular noun emphasizes that this article contains only one rule, but with three main elements: the text, its context, and the object and purpose of the treaty. Although the three paragraphs of Article 31 may appear to create a hierarchy of interpretation, the article represents a logical progression to treaty interpretation. Accordingly, one would first look at the text of the treaty, followed by context, and then look to other matters, in particular, subsequent material, in order to determine the intention of the parties.[2]

Interpreting a treaty in good faith means that even when the words of the treaty are clear, they must be interpreted in a way that would not render the meaning manifestly absurd or unreasonable. Giving a term its ordinary meaning is the most likely reflection of the intention of the treaty parties, absent some evidence to the contrary.

Paragraph 2 of Article 31, as noted above, deals with context and is a key component for treaty interpretation. The ICRC correctly notes that in addition to the text of the treaty, consideration must be given to the preamble and any annexes to the treaty (para 83-85). The provision also includes consideration of any agreement between all the parties in connection to the conclusion of the treaty or an instrument made by one or more of the parties in connection with the conclusion of the treaty.

Finally, paragraph 3 of Article 31 provides that, together with the context, there shall be taken into account any subsequent agreement between the parties regarding interpretation of the treaty or application of its provisions. There is no requirement that the subsequent agreement must itself be a treaty, although it must be “between the parties.” The most important aspect of paragraph 3 for treaty interpretation is consideration of subsequent practice by the parties. As Anthony Aust notes, “however precise a text appears to be, the way in which it is actually applied by the parties is usually a good indication of what they understand it to mean, provided the practice is consistent and common to, or accepted, expressly or tacitly, by both or all the parties.”[3]

The rule also provides that other relevant rules of international law applicable in the relations between the parties be considered. Therefore, a treaty must be interpreted within the wider context of international law. This means that an interpretation may require regard to not only international law in 1949 when the Geneva Conventions were adopted but also contemporary law of today.

Specific Concerns with ICRC’s Application of the Vienna Convention

A commentary is an excellent resource for practitioners. A noted colleague stated that practitioners will use a commentary as a starting point for treaty interpretation to discern State practice and identify academic writings on a particular topic. As such, commentaries are valuable tools for academic analysis and products (here). It is clear that the ICRC, led by Jean-Marie Henckaerts, has put tremendous effort into the Commentary on the Third Convention. As Professor Watts stated, this Commentary may reach 2000 pages once it is published. There is much in the Commentary that is helpful and provides useful guidance for practitioners.

However, there are significant issues with the methodology that detract from its objective. The ICRC departs from the established principles of treaty interpretation discussed above with the Commentary in the following ways:

(1) Substituting the ICRC’s interpretation of the object and purpose of the Convention when the original drafters specifically declined to do so;

(2) Affording too much weight to statements and writings of the ICRC, academics, and non-governmental organizations while giving insufficient weight to State practice in applying the Convention;

(3) Reliance on subsequent treaties to which certain States are not a party; and

(4) Taking an expansive interpretation of the 1949 Geneva Conventions where it was not intended by the States.

Object and Purpose

According to the updated Commentary, the overall object and purpose of the Third Convention is to ensure that prisoners of war are humanely treated at all times, while allowing belligerents to intern captured enemy combatants to prevent them from returning to the battlefield (para 89). The ICRC correctly states that a treaty will often use the preamble to set out the object and purpose. The 1949 Conventions’ preambles are very short and provide only limited guidance compared with the more substantial preambles to the Additional Protocols. After looking at the text, titles, and annexes of the Convention, the ICRC determined what it believed to be the object and purpose of the Convention.

One of the fundamental principles of treaty interpretation is to discern the intention of the parties. In this instance, the updated Commentary disregards Pictet’s original Commentary, which explained the short preamble to the 1949 Conventions. Pictet wrote that “it is not always a matter of indifference whether a treaty does or does not open with a statement of motives and a (sic) exact definition of its object.” Some delegations pushed for an expansive preamble while others disagreed. In the end, the delegations concluded that it was better not to have a preamble without consensus and the question of inserting a preamble was put to the vote and rejected by a large majority.

My concern is not with the formulation of the object and purpose crafted by the ICRC, but rather the methodology and lack of discussion regarding the disagreement of the parties in 1949. The updated Commentary’s failure to concede that States intentionally did not include a preamble that specifically set forth the object and purpose neglects the intent of the parties. Instead, the ICRC substitutes its own conclusion in their place.

State Practice

Second, the Commentary describes the appropriate approach to assessing State practice. However, as with its 2005 Customary International Humanitarian Law Study, the ICRC fails to rigorously apply the required approach. In November 2006, the Department of Defense General Counsel, Mr. William Haynes, and the Department of State Legal Adviser, Mr. John Bellinger, penned a joint letter setting forth the official U.S. government response to the Study. Two of the methodological flaws noted by the United States in that study are repeated with the updated Commentary: (1) undue weight is given to non-governmental organizations and the ICRC itself versus relying on actual practice by States parties; and (2) undue emphasis on written materials, such as military manuals or other guidelines by States versus actual operational practice.

The Commentary provides examples of State practice and cites to various military manuals of certain States. It also cites to numerous academic articles, as well as ICRC interpretations and its own writings. In my view, more weight appears to be given to the latter than the former. These scholarly articles—which do include articles written by State practitioners—can be a useful way to determine the practice of a particular State. However, care must be taken. Many articles, even when written by a practitioner, are done to advocate a certain view of the law or even argue for a change in the law. They are almost always written in the personal capacity of the author. Accordingly, these articles do not necessarily reflect the official views of their government.

Similarly, reliance on military manuals and regulations are not necessarily an accurate reflection of a State’s view of its legal obligations under a particular treaty. Manuals and regulations are not created equally. In the United States, the DoD Law of War Manual is the authoritative statement on the law of war for the Department of Defense. In August 2019, the Army and Marine Corps published The Commander’s Handbook on the Law of Land Warfare. That publication also provides guidance to Soldiers and Marines on the doctrine and practice related to customary international law and treaty law applicable to the conduct of land warfare. However, it notes that the publication “summarizes the law and practice under the [law of armed conflict] and provides “general and sometimes more narrow guidelines than might be allowed for as a matter of law” (FM 6-27, Introduction). Military manuals provide guidance to a State’s forces and for operational and policy reasons may present a more restrictive view than a particular treaty or rule under the law of war may allow.

Reliance on Subsequent Treaties

Third, the ICRC Commentary specifically references the 1977 Additional Protocols, human rights treaties, customary international law, and the law of State responsibility as evidence of other relevant rules of international law. It includes the Rome Statute of the International Criminal Court, the Convention Against Torture, the International Covenant on Civil and Political Rights, and the European Convention on Human Rights—all treaties that were developed subsequent to the Third Convention.

In trying to determine if the Additional Protocols or the other specified treaties constitute “relevant rules of international law applicable in the relations between the parties,” a treaty can be interpreted within the wider context of international law. That approach, however, is subject to limitations. The International Law Commission in its 2006 report offers guidance. Article 31(3)(c) allows an interpreter to consider other treaties to help determine a consistent meaning of a term or provision. It further notes that other rules are of “particular relevance where parties to the treaty under interpretation are also parties to the other treaty, where the treaty rule reflects customary international law, or where it provides evidence of the common understanding of the parties as to the object and purpose of the treaty under interpretation or as to the meaning of a particular term.”[4] Therefore, the Additional Protocols and other treaties cited by the ICRC may have some usefulness but are not particularly relevant until all the parties of the 1949 Geneva Conventions are also parties to those agreements or where the treaty rule reflects customary international law.

Lex Ferenda v Lex Lata

Finally, portions of the Commentary include statements of lex ferenda (law as it should be) cloaked as lex lata (law as it is).

A representative example is found in the comments on Common Article 1, which provides that “The High Contracting Parties undertake to respect and ensure respect for the present Convention in all circumstances” (paras 152-154).

The updated Commentary takes an expansive view of Common Article 1, stating that the requirement not only applies to the State in question, but also includes an external obligation. That is, the Commentary considers that Common Article 1 “requires in addition that States ensure respect for the Conventions by other States and non-State Parties.” It continues, asserting that “This view was already expressed in the 1960 ICRC Commentary. Developments in customary international law have since confirmed this view” (para 153).

In their 2016 and 2017 updated Commentaries to the First and Second Geneva Conventions, the ICRC, as Professors Mike Schmitt and Sean Watts note in a recent article, took an unqualified view that Common Article 1 included an external obligation. Many States, including the United States, however, pushed back on the conclusion reached in those two Commentaries. In this most recent Commentary, the ICRC finally reflects that “[t]here is disagreement as to the legal nature of the positive component of the duty to ensure respect by others” (para 202). However, they then refer to their own view as “reflecting the prevailing view today (para 153).”

It would be helpful, and would provide the Commentary greater credibility, if the ICRC clearly identified when statements were reflective of lex ferenda instead of disguising them as lex lata.


There are many aspects of the updated Commentary that are useful to the military practitioner. However, there remain concerns regarding the methodology in how the ICRC conducted the study. Why is this so important for a military practitioner? LTG Charles Pede, the Judge Advocate General of the U.S. Army, says it is the role of Judge Advocates to make clear what the law is to commanders. However, “the sheer volume and density of writing and publishing and commentary on the law of armed conflict presents the very real danger that people will no longer be able to tell the difference between what the law is, and what someone wants the law to be.”

It is critical for those of us who are practitioners to get the law right. It is equally important for the ICRC to get the Commentary right. Unfortunately, there are times when the methodology falls short.


Mr. Michael Meier currently serves as the Special Assistant to the Army Judge Advocate General for Law of War Matters. As the senior civilian adviser, he advises on legal and policy issues involving the law of war, reviews proposed new weapons and weapons systems, serves as a member of the DoD Law of War Working Group, and provides assistance on detainee and Enemy Prisoner of War affairs.



[1] See William P. Rogers, Letter of Submittal, Oct. 18, 1971, in Message of the President of the United States Transmitting the Vienna Convention on the Law of Treaties Signed for the United States on April 24, 1970, 92 Congress, Executive L, p. 1 (1971) (“Although not yet in force, the Convention is already generally recognized as the authoritative guide to current treaty law and practice.”).

[2] Anthony Aust, Modern Treaty Law and Practice (3rd Edition), page 208, Cambridge University Press 2013.

[3] Id. at 215.

[4] ILC Report on the works of its Fifty-eight Session (2006), General Assembly, Official Record, Sixty-First Session, Supplement No 10 (A/61/10), 414-15, para. 21.