When Do Countries Have to Investigate War Crimes?

In late August, the New York Times and others reported that the US Army had reopened a criminal investigation into the murders of at least 17 civilians in Afghanistan in 2012 and 2013. The Afghan military, which carried out its own investigation, blamed an Afghan-American interpreter and three US soldiers who were part of a Special Forces A-Team that had been interrogating the victims. Many of the bodies were found buried close to the A-Team’s base. Also according to Afghan investigators, the interpreter tortured a detainee while he was under American control and direction. The Washington Post has reported that these “unsolved killings remain among the most sensitive controversies of the American military presence in Afghanistan.”

This renewed investigation into war crimes raises a number of questions under international law, including about the duty to investigate allegations of war crimes, the duty to prosecute perpetrators, and the range of persons who can be held accountable. Is there an obligation to investigate? What triggers it? Who must carry out investigations? What standards must investigations meet? And who can be held responsible for war crimes? Below is a very brief look at some possible answers to these questions.

The duty to investigate

It is an accepted rule of customary international humanitarian law (IHL), applicable in any type of armed conflict, that “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.” This obligation to investigate and prosecute is derived from a number of IHL instruments, including the 1949 Geneva Conventions and the 1977 Additional Protocol I. The United Nations General Assembly’s 2005 Basic Principles and Guidelines on the Right to a Remedy and Reparation for Victims of Gross Violations of International Human Rights Law and Serious Violations of International Humanitarian Law also restates the obligation.

In a useful article on the topic, Amichai Cohen and Yuval Shany describe the rationale for investigations as follows:

[C]riminal investigations and prosecutions may promote respect for IHL through increased deterrence and the physical removal of violators from the battlefield. Other considerations, including learning from operational misdeeds in order to avoid future violations and the second-order obligation to satisfy victims of violations, also militate in favor of an expansive duty to investigate as an effective method to ensure respect for IHL.

Investigating war crimes

The customary IHL duty to investigate encompasses allegations of all “war crimes,” which have been described as violations that endanger protected persons (e.g., civilians, prisoners of war, the wounded and sick) or objects (e.g., civilian objects or infrastructure), or that breach important values. Most war crimes involve death, injury, destruction, or unlawful taking of property. The following are the war crimes that have been recognized under treaty and customary law: grave breaches as specified under the four Geneva Conventions of 1949 and under Additional Protocol I of 1977, including torture, taking hostages, and willful deprivation of the right to a fair and regular trial; war crimes as specified under Article 8 of the Rome Statute of the International Criminal Court, including intentionally directing attacks against the civilian population as such, civilian objects, or individual civilians not taking direct part in hostilities; and other war crimes in international and non-international armed conflicts under customary IHL, including slavery, collective punishments, and launching indiscriminate attacks resulting in loss of life or injury to civilians.

Nevertheless, experts continue to debate what types of specific events trigger the duty to investigate. At a minimum, suspected cases of war crimes would qualify. The Turkel Commission’s comparative survey of legal principles applied to investigations and inquiries of alleged IHL violations in six countries suggests the trigger is a “reasonable suspicion” that a war crime has been committed. Based on a 2011 survey of law and practice in four countries with elaborate military-justice systems, Michael Schmitt has added (emphasis added):

Every allegation of a war crime need not be investigated. The requirement to investigate applies only where such allegations appear credible. On the other hand, an investigation must be launched even in the absence of an allegation when credible reason to suspect a violation exists.

This is supported by European Court of Human Rights case law, which refers to “proof of an arguable claim” or a “credible assertion.” Of course, in certain circumstances, a fact-finding assessment will be required in order to establish a reasonable suspicion.

The allegations in the Afghan case are grim, and the unexplained deaths of 17 men who were in US Army custody ought to amount, at a minimum, to a credible reason to suspect violations.

Commanders must investigate

As for who must carry out investigations into alleged war crimes, it has been submitted that if military commanders must take measures to prevent and punish violations (as required, for example, under Article 87 of the Additional Protocol I of 1977, Article 28 of the Rome Statute, and Article 7 of the Statute of the International Criminal Tribunal for the Former Yugoslavia (ICTY)), then they must also have the obligation to carry out investigations. The ICTY has written:

A superior’s duty to punish the perpetrators of a crime may encompass an obligation to conduct an effective investigation with a view to establishing the facts. The obligation to investigate translates into an obligation on the part of the superior to take active steps to ensure that the perpetrators will be punished.

As the Second Report of the Turkel Commission explained:

The exercise of effective military authority is fundamental to ensuring compliance with the law. International humanitarian law recognizes the central role of commanders and other superiors in the context of military operations. Subordinate military forces must know that their commanders and other superiors will respond effectively to violations of international humanitarian law. Failure to do so entails legal responsibility for the military commanders and other superiors as well as for the perpetrators themselves. Commanders and other superiors have a general obligation to prevent violations of international humanitarian law and to take measures to ensure that appropriate steps are taken in response to suspected violations.

Commanders are obligated to investigate allegations of violations committed by their subordinates. In this case, the US military has reopened its criminal investigation, though as the Post notes, it may be too little too late. Tension over the murders continues to simmer, and with several years having passed in the interim, much evidence has been lost. Of course, this elicits questions about the quality that can reasonably be expected of investigations in an armed conflict.

Standards of investigation

IHL instruments do not explicitly address the form that investigations must take. As mentioned above, the ICTY has spoken of an “effective” investigation. The Rome Statute states in Article 17 that a case will not be admissible unless the State investigating or prosecuting it “is unwilling or unable genuinely to carry out the investigation or prosecution.” (Emphasis added.) The provision describes shielding a person from criminal responsibility, delays in proceedings inconsistent with intent to prosecute, proceedings that are not independent or impartial, and the collapse or unavailability for a national judicial system as signs of unwillingness or inability. In other words, as Cohen and Shany have written, a genuine investigation is “bona fide in nature, prompt, independent and impartial.”

According to investigation reports such as the 2009 Report of the United Nations Fact-Finding Mission on the Gaza Conflict, the Second Report of the Turkel Commission to Examine the Maritime Incident of 31 May 2010, and the 2015 Report of the detailed findings of the United Nations Independent Commission of Inquiry on the 2014 Gaza Conflict, to be effective, investigations should adhere to the general principles — inspired by international human rights law — of independence, impartiality, effectiveness, thoroughness, promptness and transparency. Indeed, the spokesman for the Army’s Criminal Investigation Command in Quantico, was quoted as saying (emphasis added), “All death investigations conducted by U.S. Army Criminal Investigation Command Special Agents are conducted to a thoroughness standard, not necessarily to a timetable.”

Situations of armed conflict will unquestionably bring practical challenges in carrying out investigations, and the manner in which the general principles are applied will vary according to the circumstances. As the Times reported, the Criminal Investigation Command spokesman “pointed out that carrying out a criminal investigation in a war zone posed special difficulties because of dangers to investigators, lack of access to witnesses, and ‘subject and victim identities in a foreign, austere and chaotic environment.’” Nevertheless the obligation to conduct an effective investigation remains, and no situation of armed conflict will discharge States of this duty. The spokesman added, “C.I.D. Special Agents are trained and determined to get to the truth regardless of how long that might take.”

The duty to prosecute individuals, including superiors

It is intuitive that when investigations reveal the commission of war crimes, IHL requires that individuals be held criminally responsible for the war crimes they commit. They can also be held accountable for attempting to commit a war crime, or for assisting in, facilitating, aiding, abetting, planning, or instigating the commission of a war crime.

As for commanders and other superiors, they are criminally responsible for war crimes committed or attempted by subordinates following their orders. In addition, commanders and other superiors are criminally responsible for war crimes committed by their subordinates if they knew, or had reason to know, that the subordinates were about to commit or were committing such crimes and did not take all necessary and reasonable measures in their power to prevent their commission, or, if such crimes have been committed, to punish the persons responsible. This last element about failing to punish those responsible is a natural consequence of commanders’ obligation to take measures to prevent and punish violations, including carrying out investigations.

State responsibility

In parallel to holding individuals criminal responsible, a State can be held accountable for the conduct of a person or group that is empowered to exercise governmental authority, but also if, in carrying out the conduct, the person or group is acting on the instructions of, or under the direction or control of, that State. An earlier blog post explored the legal test for determining whether a State is responsible for IHL violations by a person or group that is not exercising government authority. An even earlier post examined the duty to make reparations flowing from a State’s responsibility for committing IHL violations. 

About the Author(s)

Nathalie Weizmann

is Senior Legal Officer with the United Nations Office for the Coordination of Humanitarian Affairs.