2016 Joint Series on International Law and Armed Conflict: Ian Park on the Obligation to Investigate IHL Violations

In the fourth installment of our Transatlantic Dialogue Series, Ian Park discusses the obligation to investigate violations of IHL. Commander Ian Park has served in 7 ships and deployed worldwide in support of the Royal Navy and has deployed as a legal adviser to the ISAF Joint Command, Kabul, Afghanistan in 2011-12, and on numerous occasions to the Middle East. He regularly lectures at universities and military academies. Ian is a graduate of Oxford University, and is, or has been, a Hudson Fellow at Oxford University, a visiting fellow at Harvard Law School, and a First Sea Lord's Fellow. The views expressed in this article are the author's own and do not necessarily reflect those of the ICRC or the other blogs taking part in this series.

Here's a taste:


Understanding the parameters of a state’s obligation to investigate alleged violations of international humanitarian law is crucial to both the legitimacy of armed forces, and their military effectiveness.   If a state was unwilling, or unable, to investigate egregious behavior by their armed forces this would not only contravene their obligations under the Geneva Conventions it may lead to investigations by the International Criminal Court for those states parties to the Rome Statute, but also attract significant opprobrium.  Equally, in planning military operations, significant resources are often required to properly investigate alleged violations of IHL.  This in turn requires trained personnel in sufficient numbers to perform this function, and robust military doctrine and national legislation to guide it.  This brief paper seeks to explore the extent of the obligation to investigate alleged violations of IHL, what constitutes a ‘compliant’ investigation, and how this requirement interacts with the obligation to investigate in international human rights law.

1. To what extent does LOAC/IHL provide an obligation to investigate alleged violations?

International Armed Conflict

Rule 158 of the International Committee of the Red Cross’s Study on Customary International Law describes the obligation of states to investigate war crimes in the following terms:

States must investigate war crimes allegedly committed by their nationals or armed forces, or on their territory, and, if appropriate, prosecute the suspects. They must also investigate other war crimes over which they have jurisdiction and, if appropriate, prosecute the suspects.

The ICRC Rule 158 is reflected in numerous international instruments and supported by academic opinion. Additionally, the preamble to the Statute of the International Criminal Court recalls “the duty of every State to exercise its criminal jurisdiction over those responsible for international crimes.”  Further, the Turkel Commission convincingly asserts that ‘[…] in relation to the nature of the violations, it can be deduced from the Commentary on the Geneva Conventions that the obligation to investigate and commit for trial the perpetrators of breaches is not limited merely to those grave breaches defined as such in the Conventions, but includes all breaches of international humanitarian law that amount to ‘war crimes.’’  Finally, both the military manuals of numerous states and their practice of investigating alleged violations of IHL, support the ICRC’s assertion made in Rule 158.

Non-international Armed Conflict

Despite the fact that the duty to investigate violations of international humanitarian law is not mentioned in Common Article 3 of the Geneva Conventions, or in the Second Additional Protocol, it is submitted that the obligation also exists in non-international armed conflicts (NIACs).  This assertion is supported by state practice, ICRC Rule 158, and the findings of the Turkel Commission.  The Turkel Commission examined this issue in detail, and in support of their assertion that the obligation to investigate applies equally in a NIACs cited, inter alia,‘Article 149(3), GC IV (as well as an equivalent provision in the other three Conventions) in that there is an obligation to suppress all acts contrary to the Conventions (including, it may be assumed, acts contrary to Common Article 3); the preamble to the Rome Statute that recognizes a customary duty of States to investigate all crimes under international law, including war crimes committed in non–international armed conflicts; and the statutes for ad hoc tribunals, for example, the International Criminal Tribunal for Rwanda.’  It is further submitted that the type of investigation required and the procedures to be followed are equally applicable to IACs and NIACs.  These procedures can, however, be modified to reflect the circumstances encountered by those responsible for conducting the investigation.

Read his full post on EJIL: Talk!

Schedule of blog posts:

The joint blog series arising from the workshop follows on from our collaboration in hosting a similar series last year (see here, here and here). The Transatlantic Workshop is organized and sponsored by the Oxford Institute for Ethics, Law and Armed Conflict, the Oxford Martin Programme on Human Rights for Future Generations (both directed by Dapo Akande), the Washington DC & London delegations of  International Committee of the Red Cross, the Houston College of Law (through the good offices of Geoff Corn), and the Robert S. Strauss Center for International Security and Law at the University of Texas (directed by Bobby Chesney).

Click here for the 2015 Series.

Click here for the 2014 Series. 

For ICRC's Customary IHL Database on Prosecution of War Crimes, click here