Related Rule
United States of America
Practice Relating to Rule 153. Command Responsibility for Failure to Prevent, Punish or Report War Crimes
The US Field Manual (1956) states:
In some cases, military commanders may be responsible for war crimes committed by subordinate members of the armed forces, or other persons subject to their control. Thus, for instance, when troops commit massacres and atrocities against the civilian population of occupied territory or against prisoners of war, the responsibility may rest not only with the actual perpetrators but also with the commander … The commander is also responsible if he has actual knowledge, or should have knowledge, through reports received by him or through other means, that troops or other persons subject to his control are about to commit or have committed a war crime and he fails to take the necessary and reasonable steps to insure compliance with the law of war or to punish violators thereof. 
United States, Field Manual 27-10, The Law of Land Warfare, US Department of the Army, 18 July 1956, as modified by Change No. 1, 15 July 1976, § 501.
The US Air Force Pamphlet (1976) states:
An important illustration of the mens rea requirement relates to a commander’s responsibility to maintain discipline and preclude violations by members of his command …
Command responsibility for acts committed by subordinates arises when the specific wrongful acts in question are knowingly ordered or encouraged. In addition, the Commander is responsible if he has the actual knowledge, or should have had knowledge through reports received by him or through other means, that combatants under his control have or are about to commit criminal violations, and he culpably fails to take reasonably necessary steps to ensure compliance with the law and punish violators thereof. 
United States, Air Force Pamphlet 110-31, International Law – The Conduct of Armed Conflict and Air Operations, US Department of the Air Force, 1976, § 15-2(d).
The US Air Force Pamphlet (1976) provides: “an important illustration of the mens rea requirement relates to a commander’s responsibility to maintain discipline and preclude violations by members of his command”. 
United States, Air Force Pamphlet 110-31, International Law – The Conduct of Armed Conflict and Air Operations, US Department of the Air Force, 1976, § 15-2(d).
The US Soldier’s Manual (1984) tells soldiers:
You must report crimes immediately through your chain of command. If the crime involves your immediate superiors, report to their superior. You may also report violations of the laws of war to the inspector general, provost marshal, chaplain, or judge advocate. In any case, the law requires that you report actual or suspected violations immediately so that evidence will not be misplaced or disappear. 
United States, Your Conduct in Combat under the Law of War, Publication No. FM 27-2, Headquarters Department of the Army, Washington, November 1984, p. 27; see also p. 25.
The US Naval Handbook (1995) provides:
Officers in command are not only responsible for ensuring that they conduct all combat operations in accordance with the law of armed conflict; they are also responsible for the proper performance of their subordinates. While a commander may delegate some or all of his authority, he cannot delegate responsibility for the conduct of the forces he commands. The fact that a commander did not order, authorize, or knowingly acquiesce in a violation of the law of armed conflict by a subordinate will not relieve him of responsibility for its occurrence if it is established that he failed to exercise properly his command authority or failed otherwise to take reasonable measures to discover and correct violations that may occur. 
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-2.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Transportation, US Coast Guard, October 1995 (formerly NWP 9 (Rev. A)/FMFM 1-10, October 1989), § 6.1.3.
The manual also states: “All members of the naval service have a duty to comply with the law of armed conflict and, to the utmost of their ability and authority, to prevent violations by others.” 
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-2.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Transportation, US Coast Guard, October 1995 (formerly NWP 9 (Rev. A)/FMFM 1-10, October 1989), § 6.1.4.
The manual further states:
It is the responsibility of the Chief of Naval Operations and the Commandant of the Marine Corps to ensure that:
3. alleged violations of the law of armed conflict, whether committed by or against United States or enemy personnel, are promptly reported, thoroughly investigated, and where appropriate, remedied by corrective actions. 
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-2.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Transportation, US Coast Guard, October 1995 (formerly NWP 9 (Rev. A)/FMFM 1-10, October 1989), § 6.1.2.
The manual further provides: “All members of the naval service … have an affirmative obligation to report promptly violations of which they become aware.” 
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-2.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Transportation, US Coast Guard, October 1995 (formerly NWP 9 (Rev. A)/FMFM 1-10, October 1989), § 6.1.4.
The Annotated Supplement to the US Naval Handbook (1997) states:
A commander at any level is personally responsible for the criminal acts of warfare committed by a subordinate if the commander knew in advance of the breach about to be committed and had the ability to prevent it, but failed to take the appropriate action to do so. In determining the personal responsibility of the commander, the element of knowledge may be presumed if the commander had information which should have enabled him or her to conclude under the circumstances that such a breach was to be expected. Officers in command are also personally responsible for unlawful acts of warfare performed by subordinates when such acts are committed by order, authorization, or acquiescence of a superior. Those acts will each be determined objectively. 
United States, Annotated Supplement to the Commander’s Handbook on the Law of Naval Operations, prepared by the Oceans Law and Policy Department, Center for Naval Warfare Studies, Naval War College, Newport, Rhode Island, November 1997, § 6.1.3, footnote 13.
The Annotated Supplement also states:
Where U.S. personnel are involved, military personnel with supervisory authority have a duty to prevent criminal acts. Any person in the naval service who sees a criminal act about to be committed must act to prevent it to the utmost of his or her ability and to the extent of his or her authority … Possible actions include moral arguments to dissuade, threatening to report the criminal act, repeating orders of superiors, stating personal disagreement, and asking the senior individual on scene to intervene as a means of preventing the criminal act. In the event the criminal act directly and imminently endangers a person’s life (including the life of another person lawfully under his or her custody), force may be used to the extent necessary to prevent the crime. However, the use of deadly force is rarely justified; it may be used only to protect life and only under conditions of extreme necessity as a last resort when lesser means are clearly inadequate to protect life. 
United States, Annotated Supplement to the Commander’s Handbook on the Law of Naval Operations, prepared by the Oceans Law and Policy Department, Center for Naval Warfare Studies, Naval War College, Newport, Rhode Island, November 1997, § 6.1.4, footnote 14.
The US Manual for Military Commissions (2007), Part IV, Crimes and Elements, states:
Any person is punishable as a principal under this chapter who –
(1) commits an offense punishable by this chapter, or aids, abets, counsels, commands, or procures its commission;
(2) causes an act to be done which if directly performed by him would be punishable by this chapter; or
(3) is a superior commander who, with regard to acts punishable under this chapter, knew, had reason to know, or should have known, that a subordinate was about to commit such acts or had done so and who failed to take the necessary and reasonable measures to prevent such acts or to punish the perpetrators thereof. 
United States, Manual for Military Commissions, published in implementation of the Military Commissions Act of 2006, 10 U.S.C. §§ 948a, et seq., 18 January 2007, Part IV, § 1(a), p. IV-1.
The US Naval Handbook (2007) states:
A naval commander may delegate some or all of his authority; however, he cannot delegate his accountability for the conduct of the forces he commands. Under the law of armed conflict, a commander may be held … responsible for the acts of subordinates when the commander knew, or should have known, that subordinates under his control were going to commit or had committed violations of the law of armed conflict and he failed to exercise properly his command authority or failed otherwise to take reasonable measures to discover and correct violations that may occur. 
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-12.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Homeland Security, US Coast Guard, July 2007, § 6.1.3.
The Handbook also states:
DOD [Department of Defense] Directive 2311.01E, DOD Law of War Program is the DOD source for law of war reporting requirements. This directive defines a reportable incident as “a possible, suspected, or alleged violation of the law of war, for which there is credible information, or conduct during military operations other than war that would constitute a violation of the law of war if it occurred during an armed conflict.” Such incidents must be “promptly reported, thoroughly investigated, and, where appropriate, remedied by corrective action.”
All military and U.S. civilian employees and contractor personnel assigned to or accompanying a DOD component shall report incidents through the chain of command. The commander of any unit that obtains information about a reportable incident shall immediately report the incident through command channels to operational and military department higher authorities. 
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-12.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Homeland Security, US Coast Guard, July 2007, § 6.3.
The US Manual for Military Commissions (2010), Part IV, Crimes and Elements, states:
Principals
Any person punishable under this chapter who—
(1) commits an offense punishable by this chapter, or aids, abets, counsels, commands, or procures its commission;
(2) causes an act to be done which if directly performed by him would be punishable by this chapter; or
(3) is a superior commander who, with regard to acts punishable under this chapter, knew, had reason to know, or should have known, that a subordinate was about to commit such acts or had done so and who failed to take the necessary and reasonable measures to prevent such acts or to punish the perpetrators thereof is a principal. 
United States, Manual for Military Commissions, published in implementation of Chapter 47A of Title 10, United States Code, as amended by the Military Commissions Act of 2009, 10 U.S.C, §§ 948a, et seq., 27 April 2010, § 2, p. IV-2.
The US Regulations Governing the Trials of Accused War Criminals in the Pacific Region I (1945), establishing provisions for the punishment of a list of more specific offences and also of “all other offences against the laws or customs of war”, provided for the punishment of “participation in a common plan or conspiracy to accomplish any of [these acts]”. It stated:
Leaders, organizers, instigators, accessories and accomplices participating in the formulation or execution of any such common plan or conspiracy will be held responsible for all acts performed by any person in execution of that plan or conspiracy. 
United States, Regulations Governing the Trials of Accused War Criminals in the Pacific Region I, 1945, Regulation 5.
The US Military Commissions Act (2009) amends Chapter 47A of Title 10 of the United States Code as follows:
§ 950q. Principals
“Any person punishable under this chapter who—
“(1) commits an offense punishable by this chapter, or aids, abets, counsels, commands, or procures its commission;
“(2) causes an act to be done which if directly performed by him would be punishable by this chapter; or
“(3) is a superior commander who, with regard to acts punishable by this chapter, knew, had reason to know, or should have known, that a subordinate was about to commit such acts or had done so and who failed to take the necessary and reasonable measures to prevent such acts or to punish the perpetrators thereof, is a principal. 
United States, Military Commissions Act, 2009, § 950q.
In its judgment in the Von Leeb case (The German High Command Trial) in 1947/48 relative to the duty of commanders in occupied territory, the US Military Tribunal at Nuremberg, under the heading “Responsibility of a Commanding Officer for Acts not Ordered by Him”, stated:
Criminality does not attach to every individual in [the] chain of command from that fact alone. There must be a personal dereliction. That can occur only where the act is directly traceable to [the commander] or where his failure to properly supervise his subordinates constitutes criminal negligence on his part. In the latter case, it must be a personal neglect amounting to a wanton, immoral disregard of the action of his subordinates amounting to acquiescence. Any other interpretation of International Law would go far beyond the basic principles of criminal law as known to civilized nations. 
United States, Military Tribunal at Nuremberg, Von Leeb case (The German High Command Trial), Judgment, 30 December 1947–28 October 1948.
However, the Tribunal also noted:
It is the opinion of this Tribunal that a State can, as to certain matters, under International Law, limit the exercise of sovereign powers by a military commander in an occupied area, but we are also of the opinion that under International Law and accepted usages of civilized nations, that he has certain responsibilities which he cannot set aside or ignore by reason of activities of his own State within his area … The situation is somewhat analogous to the accepted principle of International Law that the army which captures the soldiers of its adversary has certain fixed responsibilities as to their care and treatment. 
United States, Military Tribunal at Nuremberg, Von Leeb case (The German High Command Trial), Judgment, 30 December 1947–28 October 1948.
In its judgment in the List case (The Hostages Trial) in 1947/48, the US Military Tribunal at Nuremberg stated:
We have herein before pointed out that it is the duty of the commanding general in occupied territory to maintain peace and order, punish crimes and protect lives and property. This duty extends not only to inhabitants of the occupied territory but to his own troops and auxiliaries as well … The duty and responsibility for maintaining peace and order, and the prevention of crime rests upon the commanding general. He cannot ignore obvious facts and plead ignorance as a defence … Those responsible for such crimes [i.e. violations of the 1907 Hague Regulations] by ordering or authorizing their commission, or by a failure to take effective steps to prevent their execution or recurrence, must be held to account if International Law is to be anything more than an ethical code, barren of any practical coercive deterrent. 
United States, Military Tribunal at Nuremberg, List case (The Hostages Trial), Judgment, 8 July 1947–19 February 1948.
With regard to the accused, a high-ranking officer charged with murder and deportation of civilians, the Tribunal stated:
Not once did he condemn such acts as unlawful. Not once did he call to account those responsible for these inhumane and barbarous acts. His failure to terminate these unlawful killings and to take adequate steps to prevent their recurrence constitutes a serious breach of duty and imposes criminal responsibility … [A] commanding general of occupied territory cannot escape responsibility by a claim of a want of authority. The authority is inherent in his position as commanding general of occupied territory. The primary responsibility for the prevention and punishment of crime lies with the commanding general, a responsibility from which he cannot escape by denying his authority over the perpetrators. 
United States, Military Tribunal at Nuremberg, List case (The Hostages Trial), Judgment, 8 July 1947–19 February 1948.
In the Yamashita case in 1946 involving the trial of the military governor and commanding general of Japan in the Philippines between 9 October 1944 and 2 September 1945, the US Supreme Court was called upon to decide whether the accused could be held responsible for the violations of IHL committed by the troops under his command. The charge alleged that the accused, even though he did not commit or direct the commission of the acts,
while commander of armed forces of Japan at war with the United States of America and its allies, unlawfully disregarded and failed to discharge his duty as commander to control the operations of the members of his command, permitting them to commit brutal atrocities and other high crimes against the people of the United States and of its allies and dependencies, particularly the Philippines; and he … thereby violated the laws of war. 
United States, Supreme Court, Yamashita case, Judgment, 4 February 1946.
The Court, in upholding the finding of guilt by the Military Commission in Manila, emphasized that:
It is evident that the conduct of military operations by troops whose excesses are unrestrained by the orders or efforts of their commander would almost certainly result in violations which it is the purpose of the law of war to prevent. Its purpose to protect civilian populations and prisoners of war from brutality would largely be defeated if the commander of an invading army could with impunity neglect to take reasonable measures for their protection. Hence, the law of war presupposes that its violation is to be avoided through the control of the operations of war by commanders who are to some extent responsible for their subordinates.  
United States, Supreme Court, Yamashita case, Judgment, 4 February 1946.
The Court based its decision on Article 1 of the 1907 Hague Regulations, Article 19 of the 1907 Hague Convention (X), Article 26 of the 1929 Geneva Convention and Article 43 of the 1907 Hague Regulations and stated:
These provisions plainly imposed on petitioner, who at the time specified was military governor of the Philippines, as well as commander of the Japanese forces, an affirmative duty to take such measures as were within his power and appropriate in the circumstances to protect prisoners of war and the civilian population. 
United States, Supreme Court, Yamashita case, Judgment, 4 February 1946.
One of the judges, in his dissenting opinion, discussed the problem of finding upon a commander’s guilt in the case where the troops of a commander commit war crimes while under heavily adverse battle conditions. The judge stated:
There are numerous instances, especially with reference to the Philippines insurrection in 1900 and 1901, where commanding officers were found to have violated the laws of war by specifically ordering members of their command to commit atrocities and other war crimes … And in other cases officers have been held liable where they knew that a crime was to be committed, had the power to prevent it and failed to exercise that power … In no recorded instance, however, has the mere inability to control troops under fire or attack by superior forces been made the basis of a charge of violating the laws of war … No one denies that inaction or negligence may give rise to liability, civil or criminal. But it is quite another thing to say that the inability to control troops under highly competitive and disastrous battle conditions renders one guilty of a war crime in the absence of personal culpability. Had there been some element of knowledge or direct connection with the atrocities the problem would be entirely different … The only conclusion I can draw is that the charge made against the petitioner is clearly without precedent in international law or in the annals of recorded military history. This is not to say that enemy commanders may escape punishment for clear and unlawful failures to prevent atrocities. But that punishment should be based upon charges fairly drawn in light of established rules of international law and recognized concepts of justice. 
United States, Supreme Court, Yamashita case, Dissenting opinion of Mr. Justice Murphy, 4 February 1946.
Another judge, in his dissenting opinion, referred to the first dissenting opinion and stated that he had “discussed the charge with respect to the substance of the crime. With his conclusions in this respect I agree.” He further stressed that the findings on evidence did not suffice legal requirements:
There is no suggestion in the findings that petitioner personally participated in, was present at the occurrence of, or ordered any of these incidents … Nor is there any express finding that he knew of any one of the incidents in particular or of all taken together. The only inferential findings that he had knowledge, or that the commission so found, are in the statement that “crimes alleged to have been permitted by the accused in violation of the laws of war may be grouped into three categories” set out below. In the further statement that “the prosecution presented evidence to show that the crimes were so extensive and widespread, both as to time and area, that they must either have been wilfully permitted by the accused, or secretly ordered by” him; and in the conclusions of guilt and the sentence. Indeed, the commission’s ultimate findings draw no express conclusion of knowledge, but state only two things: (1) the fact of widespread atrocities and crimes; (2) that petitioner “failed to provide effective control … as was required by the circumstances” … In the state of things petitioner has been convicted of a crime in which knowledge is an essential element. 
United States, Supreme Court, Yamashita case, Dissenting opinion of Mr. Justice Rutledge, 4 February 1946.
In the Toyoda case in 1949, a US military tribunal at Tokyo considered the essential elements of command responsibility to be:
1. That offenses, commonly recognized as atrocities, were committed by troops of his command;
2. The ordering of such atrocities.
In the absence of proof beyond reasonable doubt of the issuance of orders then the essential elements of command responsibility are:
1. As before, that atrocities were actually committed;
2. Notice of the commission thereof. This notice may be either:
a. Actual, …
b. Constructive …
3. Power of command. That is, the accused must be proved to have had actual authority over the offenders to issue orders to them not to commit illegal acts, and to punish offenders.
4. Failure to take such appropriate measures as are within his power to control the troops under his command and to prevent acts which are violations of the laws of war.
5. Failure to punish offenders.
In the simplest language, it may be said that this Tribunal believes the principle of command responsibility to be that, if this accused knew, or should by the exercise of ordinary diligence have learned, of the commission by his subordinates, immediate or otherwise, of the atrocities proved beyond a shadow of a doubt before this Tribunal or of the existence of a routine which would countenance such, and, by his failure to take any action to punish the perpetrators, permitted the atrocities to continue, he has failed in his performance of his duty as a commander and must be punished. 
United States, Military Tribunal, Tokyo, Toyoda case, Trial Transcript, 6 September 1949.
In its judgment in the Karadžić case in 1995, the US Court of Appeals for the Second Circuit, recalling the judgment in the Yamashita case, stated: “International law imposes an affirmative duty on military commanders to take appropriate measures within their power to control troops under their command for the prevention of such atrocities [i.e. war crimes]”. 
United States, Court of Appeals for the Second Circuit, Karadžić case, Judgment, 13 October 1995.
In the Ford v. García case in 2000, a civil lawsuit dealing with acts of torture and extrajudicial killing committed in 1980 in El Salvador, the US Federal Court of Florida gave instructions to the jury on the issue of the responsibility of commanders which read:
A commander may be held liable for torture and extrajudicial killing committed by troops under his command under two separate legal theories. The first applies when a commander takes a positive act, i.e., he orders torture and extrajudicial killing or actually participates in it. The second legal theory applies when a commander fails to take appropriate action to control his troops. This is called the doctrine of command responsibility … The doctrine of command responsibility is founded on the principle that a military commander is obligated, under international law and United States law, to take appropriate measures within his power to control the troops under his command and prevent them from committing torture and extrajudicial killing …
To hold a specific defendant/commander liable under the doctrine of command responsibility, each plaintiff must prove all of the following elements by a preponderance of the evidence.
(1) That persons under defendant’s effective command had committed, were committing, or were about to commit torture and extrajudicial killing, and
(2) The defendant knew, or owing to the circumstances at the time, should have known, that persons under his effective command had committed, were committing, or were about to commit torture and extrajudicial killing; and
(3) The defendant failed to take all necessary and reasonable measures within his power to prevent or repress the commission of torture and extrajudicial killing, or failed to investigate the events in an effort to punish the perpetrators.
“Effective command” means the commander has the legal authority and the practical ability to exert control over his troops. A commander cannot, however, be excused from his duties where his own actions cause or significantly contribute to the lack of effective control.
A commander may be relieved of the duty to investigate or to punish wrongdoers if a higher military or civilian authority establishes a mechanism to identify and punish the wrongdoers. In such a situation, the commander must do nothing to impede nor frustrate the investigation.
A commander may fulfil his duty to investigate and punish wrongdoers if he delegates this duty to a responsible subordinate. A commander has the right to assume that assignments entrusted to a responsible subordinate will be properly executed. On the other hand, the duty to investigate and punish will not be fulfilled if the commander knows or reasonably should know that the subordinate will not carry out his assignment in good faith, or if the commander impedes or frustrates the investigation. 
United States, Federal Court of Florida, Ford v. García case, Judgment, 3 November 2000.
[emphasis in original]
At the CDDH, the United States stated:
The word “feasible” when used in draft [Additional] Protocol I, for example in Articles 50 and 51 [57 and 58], refers to that which is practicable or practically possible, taking into account all circumstances at the time, including those relevant to the success of military operations. 
United States, Statement at the CDDH, Official Records, Vol. VI, CDDH/SR.42, 27 May 1977, p. 241.
The 1979 version of the US Department of Defense Directive on the Law of War Program stated:
It is the policy of the Department of Defense to ensure that:
3. Alleged violations of the law of war, whether committed by or against U.S. or enemy personnel, are promptly reported, thoroughly investigated, and, where appropriate, remedied by corrective action.
4. Violations of the law of war alleged to have been committed by or against allied military or civilian personnel shall be reported through appropriate command channels for ultimate transmission to appropriate agencies of allied governments. 
United States, Department of Defense Directive on the Law of War Program No. 5100.77, 10 July 1979, Section C(3) and (4).
In 1992, in its final report to Congress on the conduct of the Gulf War, the US Department of Defense stated:
[Department of Defense Directive on the Law of War Program No. 5100.77] is the foundation for the US military law of war program. It contains four policies:
• Alleged violations of the law of war, whether committed by or against US or enemy personnel, … [will/shall be] promptly reported, thoroughly investigated, and, where appropriate, remedied by corrective action.
• Violations of the law of war alleged to have been committed by or against allied military or civilian personnel shall be reported through appropriate military command channels for ultimate transmission to appropriate agencies of allied governments.
Army Chief of Staff Regulation 11-2 assigns to the Army Judge Advocate General (JAG) responsibility for investigating, collecting, collating, evaluating, and reporting in connection with war crimes alleged to have been committed against US personnel.
Criminal responsibility for violations of the law of war rests with a commander, including the national leadership, if he (or she):
● Orders or permits the offence to be committed, or
● Knew or should have known of the offence(s), had the means to prevent or halt them, and failed to do all which he was capable of doing to prevent the offences or their recurrence.
The crimes committed against Kuwaiti civilians and property, and against third party nationals, are offences for which Saddam Hussein, officials of the Ba’ath Party, and his subordinates bear direct responsibility. However, the principal responsibility rests with Saddam Hussein. Saddam Hussein’s C2 [command and control] of Iraqi military and security forces appeared to be total and unequivocal. There is substantial evidence that each act alleged was taken as a result of his orders, or was taken with his knowledge and approval, or was an act which he should have known. 
United States, Department of Defense, Final Report to Congress on the Conduct of the Persian Gulf War, 10 April 1992, Appendix O, The Role of the Law of War, ILM, Vol. 31, 1992, pp. 633–636.
In 1992, the US report on Iraqi war crimes (Desert Shield/Desert Storm), prepared under the auspices of the US Secretary of the Army, noted:
Criminal responsibility for violations of the law of war rests with a commander, including the national leadership, who … knew or should have known of the offences, had the means to prevent or halt them, and failed to do all which he or she was capable of doing to prevent the offences or their recurrence. 
United States, Secretary of the Army, Report on Iraqi war crimes (Desert Shield/Desert Storm), unclassified version, 8 January 1992, p. 13.
In 1993, during a debate in the UN Security Council following the unanimous vote on Resolution 827 (1993) establishing the International Criminal Tribunal for the former Yugoslavia (ICTY), the United States stated:
With respect to paragraph 1 of Article 7 [of the 1993 ICTY Statute], it is our understanding that individual responsibility arises in the case of … the failure of a superior – whether political or military – to take reasonable steps to prevent or punish [violations of IHL] by persons under his or her authority. 
United States, Statement before the UN Security Council, UN Doc. S/PV.3217 (Provisional), 25 May 1993, p. 16.
The 1998 version of the US Department of Defense (DoD) Directive on the Law of War Program stated:
It is DoD policy to ensure that:
4.3. All reportable incidents committed by or against U.S. or enemy persons are promptly reported, thoroughly investigated, and, when appropriate, remedied by corrective action.
4.4. All reportable incidents committed by or against allied persons, or by or against other persons during a conflict to which the U.S. is not a party, are reported through command channels for ultimate transmission to appropriate U.S. Agencies, allied governments, or other appropriate authorities. 
United States, Department of Defence Directive on the Law of War Program No. 5100.77, 9 December 1998, Section 4(4)(3) and (4)(4).
A “reportable incident” is defined as “a possible, suspected, or alleged violation of the law of war”. 
United States, Department of Defence Directive on the Law of War Program No. 5100.77, 9 December 1998, Section 3(2).
As to responsibilities, the Directive provides:
The Secretaries of the Military Departments shall develop internal policies and procedures consistent with this Directive in support of the DoD Law of War Program to: … [p]rovide for the prompt reporting and investigation of reportable incidents committed by or against members of their respective Military Departments, or persons accompanying them. 
United States, Department of Defence Directive on the Law of War Program No. 5100.77, 9 December 1998, Section 5(5)(3).
The Directive further states that the Commanders of the Combatant Commands shall
issue directives to ensure that reportable incidents involving U.S. or enemy persons are reported promptly to appropriate authorities, are thoroughly investigated, and the results of such investigations are promptly forwarded to the applicable Military Department or other appropriate authorities. 
United States, Department of Defence Directive on the Law of War Program No. 5100.77, 9 December 1998, Section 5(8)(4).
Under a provision entitled “Reports of incidents”, the Directive states:
All military and civilian personnel assigned to or accompanying a DoD Component shall report reportable incidents through their chain of command. Such reports … may also be made through other channels, such as the military police, a judge advocate, or an Inspector General. Reports that are made to officials other than those specified in this subsection shall, nonetheless, be accepted and immediately forwarded through the recipient’s chain of command. 
United States, Department of Defence Directive on the Law of War Program No. 5100.77, 9 December 1998, Section 6(1).
On 8 May 2004, during his weekly radio address, the US President spoke of recent public revelations regarding the abuse of detainees at Abu Ghraib prison in Iraq by US Army personnel:
In recent days, America and the world have learned of shocking conduct in Iraqi prisons by a small number of American servicemen and women. These individuals had been given the responsibility of overseeing Iraqis in American custody, and doing so in a decent and humane manner, consistent with U.S. law and the Geneva conventions. Instead we have seen shameful images of prisoners being subjected to abuse and humiliation. Such practices do not reflect our values. They are a stain on our country’s honor and reputation.
Shortly after reports of abuse became known to our military, an investigation was launched. Today several formal investigations, led by senior military officials, are underway. Some soldiers have already been charged with crimes. We will learn all the facts and determine the full extent of these abuses. Those involved will be identified; they will answer for their actions. All prison operations in Iraq will be thoroughly reviewed to make certain that similar disgraceful incidents are never repeated. 
United States, President George W. Bush, transcript of a weekly radio address which discussed the abuse of detainees at Abu Ghraib prison, Iraq, by US Army personnel, 8 May 2004.
In 2005, the US Department of Defense (DoD) released a report of an investigation, dated 1 April 2005 (as amended 9 June 2005), commissioned by the Commander US Southern Command (USSOUTHCOM) and conducted by Lieutenant General R.M. Schmidt and Brigadier General J.T. Furlow, into FBI allegations of detainee abuse at the US Detention Facility, Joint Task Force Guantanamo Bay, Cuba. The executive summary of the report stated:
Detention and interrogation operations at Joint Task Force Guantanamo (JTF-GTMO) cover a three-year period and over 24,000 interrogations. This AR 15-6 [Army Regulation 15-6: Procedures for Investigating Officers and Boards of Officers, dated 30 September 1996] investigation found only three interrogation acts in violation of interrogation techniques authorized by Army Field Manual 34–52 [Intelligence Interrogation] and DoD guidance. The AR 15-6 also found that the Commander of JTF-GTMO failed to monitor the interrogation of one high value detainee in late 2002. The AR 15-6 found that the interrogation of this same high value detainee resulted in degrading and abusive treatment but did not rise to the level of being inhumane treatment. Finally, the AR 15-6 found that the communication of a threat to another high value detainee was in violation of SECDEF [US Secretary Department of Defense] guidance and the UCMJ [Uniform Code of Military Justice]. The AR 15-6 found no evidence of torture or inhumane treatment at JTF-GTMO. 
United States, Department of Defense, Commander United States Southern Command, Investigation into FBI Allegations of Detainee Abuse at Guantanamo Bay, Cuba Detention Facility, 1 April 2005 (as amended 9 June 2005).