Related Rule
United States of America
Practice Relating to Rule 157. Jurisdiction over War Crimes
The US Field Manual (1956) provides: “War crimes are within the jurisdiction of general courts-martial … military commissions, provost courts, military government courts, and other military tribunals … of the United States, as well as of international tribunals.” 
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, § 505(d).
The manual adds:
Each High Contracting Party [to the 1949 Geneva Conventions] shall be under the obligation to search for persons alleged to have committed, or to have ordered to be committed, … grave breaches [of the said Conventions] and shall bring such persons, regardless of their nationality, before its own courts …
[These] principles … are declaratory of the obligations of belligerents under customary international law to take measures for the punishment of war crimes committed by all persons, including members of a belligerent’s own armed forces …
The jurisdiction of United States military tribunals in connection with war crimes is not limited to offenses committed against nationals of the United States but extends also to all offenses of this nature committed against nationals of allies and of cobelligerents and stateless persons …
The United States normally punishes war crimes as such only if they are committed by enemy nationals or by persons serving the interests of the enemy State. Violations of the law of war committed by persons subject to the military law of the United States will usually constitute violations of the Uniform Code of Military Justice and, if so, will be prosecuted under that Code. Violations of the law of war committed within the United States by other persons will usually constitute violations of federal or state criminal law and preferably will be prosecuted under such law … Commanding officers of United States troops must insure that war crimes committed by members of their forces against enemy personnel are promptly and adequately punished. 
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, §§ 506(a) and (b) and 507(a) and (b).
The US Air Force Pamphlet (1976) states:
Domestic tribunals have the competence and, under the grave breaches articles of the [1949] Geneva Conventions, the strict obligation to punish certain violations … Ad hoc international tribunals, such as those established in Germany and Japan following World War II, did punish individuals for their personal actions violating the law of armed conflict. However, the importance of criminal responsibility … primarily relates to a state’s own efforts to enforce the law of armed conflict with respect to its own armed forces. 
United States, Air Force Pamphlet 110-31, International Law – The Conduct of Armed Conflict and Air Operations, US Department of the Air Force, 1976, § 10-6.
[emphasis in original]
The Pamphlet further states:
Within the [1949] Geneva Conventions system, state responsibility to repress breaches is stressed, and no provision is made for international tribunals within the Conventions …
In the United States, jurisdiction is not limited to offenses against US nationals but extends to offenses against victims of other nationalities. Violations by adversary personnel, when appropriate, are tried as offenses against international law which forms part of the law of the United States. In occupied territories, trials are usually held under occupation law. Trials of such personnel have been held in regular military courts, military commissions, provost courts, military government courts, and other military tribunals of the United States, as well as in international tribunals. 
United States, Air Force Pamphlet 110-31, International Law – The Conduct of Armed Conflict and Air Operations, US Department of the Air Force, 1976, §§ 15–3(a) and 15-4(a).
The US Naval Handbook (1995) provides:
3.11.1 … International law generally recognizes five bases for the exercise of criminal jurisdiction: (a) territorial, (b) nationality, (c) passive personality, (d) protective, and (e) universal. It is important to note that international law governs the rights and obligations between nations. While individuals may benefit from the application of that body of law, its alleged violation cannot usually be raised by an individual defendant to defeat a criminal prosecution.
3.11.1.1 Territorial Principle. This principle recognizes the right of a nation to proscribe conduct within its territorial borders, including its internal waters, archipelagic waters, and territorial sea.
3.11.1.1.1 Objective Territorial Principle. This variant of the territorial principle recognizes that a nation may apply its laws to acts committed beyond its territory which have their effect in the territory of that nation …
3.11.1.2 Nationality Principle. This principle is based on the concept that a nation has jurisdiction over objects and persons having the nationality of that nation … Under the nationality principle a nation may apply its laws to its nationals wherever they may be … As a matter of international comity and respect for foreign sovereignty, the United States refrains from exercising that jurisdiction in foreign territory.
3.11.1.3 Passive Personality Principle. Under this principle, jurisdiction is based on the nationality of the victim, irrespective of where the crime occurred or the nationality of the offender …
3.11.1.4 Protective Principle. This principle recognizes the right of a nation to prosecute acts which have a significant adverse impact on its national security or governmental functions …
3.11.1.5 Universal Principle. This principle recognizes that certain offenses are so heinous and so widely condemned that any nation may apprehend, prosecute and punish that offender on behalf of the world community regardless of the nationality of the offender or victim. Piracy and the slave trade have historically fit these criteria. More recently, genocide, certain war crimes, hostage taking, and aircraft hijacking have been added to the list of such universal crimes. 
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), §§ 3.11.1–3.11.1.5.
The Handbook also states: “International law also provides that belligerents have the right to punish enemy armed forces personnel and enemy civilians who fall under their control for [war crimes].” 
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), § 6.2.5.
The Handbook further states:
Except for war crimes trials conducted by the Allies after World War II, the majority of prosecutions for violations of the law of armed conflict have been trials of one’s own forces for breaches of military discipline. Violations of the law of armed conflict committed by persons subject to the military law of the United States will usually constitute violations of the Uniform Code of Military Justice and, if so, will be prosecuted under that Code.
Although jurisdiction extends to enemy personnel, trials have almost exclusively been against unlawful combatants, such as persons who take part in combat operations without distinguishing themselves clearly from the civilian population during battle or those acting without state sanction for private ends.
In the United States, its territories and possessions, jurisdiction is not limited to offenses against U.S. nationals, but extends to offenses against persons of other nationalities. Violations by enemy nationals may be tried as offenses against international law, which forms part of the law of the United States. In occupied territories, trials are usually held under occupation law. Trials of such personnel have been held in military courts, military commissions, provost courts, military government courts, and other military tribunals. 
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), § 6.2.5.3.
The US Naval Handbook (2007) states:
3.11.1 Jurisdiction to Proscribe
International law generally recognizes five bases for the exercise of criminal jurisdiction: (a) territorial, (b) nationality, (c) passive personality, (d) protective, and (e) universal. It is important to note that international law governs the rights and obligations between nations. While individuals may benefit from the application of that body of law, its alleged violation cannot usually be raised by an individual defendant to defeat a criminal prosecution.
3.11.1.6 Universal Principle
This principle recognizes that certain offenses are so heinous and so widely condemned that any nation may apprehend, prosecute, and punish that offender on behalf of the world community regardless of the nationality of the offender or victim. Piracy and the slave trade have historically fit these criteria. More recently, genocide, certain war crimes, hostage taking, and aircraft hijacking have been added to the list of such universal crimes. 
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, §§ 3.11.1 and 3.11.1.6.
The Handbook also states:
For offenses committed in the United States, its territories and possessions, jurisdiction is not limited to offenses by U.S. nationals, but also extends to offenses by persons of other nationalities. War crimes committed by enemy nationals may be tried as offenses against international law, which forms part of the law of the United States. Trials of enemy personnel may be held in U.S. federal courts, military courts, and military tribunals or commissions. In occupied territories, trials are usually held under occupation law. Trials of such personnel have been held in military courts, military commissions, provost courts, military government courts, and other military tribunals. 
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, § 6.2.6.2.
The US Convention on Genocide Implementation Act (1987) includes the following conditions as a required circumstance for the alleged offences:
(1) the offense is committed within the United States; or
(2) the alleged offender is a national of the United States (as defined in section 101 of the Immigration and Nationality Act (8 U.S.C. 1101)). 
United States, Convention on Genocide Implementation Act, 1987, Section 1091(d).
The US Convention against Torture Implementation Act (1994), which provides for the punishment of acts of torture committed outside the United States, provides:
There is jurisdiction over [acts of torture] if –
(1) the alleged offender is a national of the United States; or
(2) the alleged offender is present in the United States, irrespective of the nationality of the victim or alleged offender. 
United States, Convention against Torture Implementation Act, 1994, Section 2340A(b).
The US War Crimes Act (1996) provides:
(a) Offense. – Whoever, whether inside or outside the United States, commits a war crime, in any of the circumstances described in subsection (b), shall be fined under this title or imprisoned for life or any term of years, or both, and if death results to the victim, shall also be subject to the penalty of death.
(b) Circumstances. – The circumstances referred to in subsection (a) are that the person committing such war crime or the victim of such war crime is a member of the Armed Forces of the United States or a national of the United States (as defined in section 101 of the Immigration and Nationality Act). 
United States, War Crimes Act, 1996, Section 2441(a) and (b).
In its judgment in the Altstötter case (The Justice Trial) in 1947, the US Military Tribunal at Nuremberg stated:
As to the punishment of persons guilty of violating the laws and customs of war (war crimes in the narrow sense), it has always been recognised that tribunals may be established and punishment imposed by the State in whose hands the perpetrators fall. Those rules of international law were recognised as paramount, and jurisdiction to enforce them by the injured belligerent government, whether within the territorial boundaries of the State or in occupied territory, has been unquestioned … However, enforcement of international law has been traditionally subject to practical limitations. Within territorial boundaries of a State having a recognised, functioning government presently in the exercise of sovereign power throughout its territory, a violator of the rules of international law could be punished only by the authority of the officials of that State. The law is universal, but such a State reserves unto itself the exclusive power within its boundaries to apply or withhold sanctions.
Thus, notwithstanding the paramount authority of the substantive rules of common international law the doctrines of national sovereignty have been preserved through the control of enforcement machinery. It must be admitted that Germans were not the only ones who were guilty of committing war crimes; other violators of international law could, no doubt, be tried and punished by the State of which they were nationals, by the offended State if it can secure jurisdiction of the person, or by an International Tribunal if of competent authorised jurisdiction.
Applying these principles, it appears that the power to punish violators of international law in Germany is not solely dependent on the enactment of rules of substantive penal law applicable only in Germany. Nor is the apparent immunity from prosecution of criminals in other States based on the absence there of the rules of international law which we enforce here. Only by giving consideration to the extraordinary and temporary situation in Germany can the procedure here be harmonised with established principles of national sovereignty. In Germany an international body (the Control Council) has assumed and exercised the power to establish judicial machinery for the punishment of those who have violated the rules of common international law, a power which no international authority without consent could assume or exercise within a State having a national government presently in the exercise of its sovereign powers. 
United States, Military Tribunal at Nuremberg, Altstötter case (The Justice Trial), Judgment, 4 December 1947.
In the Demjanjuk case in 1985, a US Court of Appeals recognized Israel’s right to try a person accused of war crimes on the basis of universal jurisdiction and rejected an appeal to overturn an extradition order. The Court held:
The universality principle is based on the assumption that some crimes are so universally condemned that the perpetrators are the enemies of all people. Therefore, any nation which has custody of the perpetrators may punish them according to its law applicable to such offences … Israel or any other nation … may undertake to vindicate the interest of all nations by seeking to punish the perpetrators of such crimes. 
United States, Court of Appeals, Demjanjuk case, Judgment, 31 October 1985.
In 2003, in the Yousef case, involving appeals against judgments of conviction on charges related to involvement in the 1993 bombing of the World Trade Centre and a conspiracy to bomb 12 US commercial aircraft in South-east Asia in 1994, the US Court of Appeals, Second Circuit, held:
The historical restriction of universal jurisdiction to piracy, war crimes, and crimes against humanity demonstrates that universal jurisdiction arises under customary international law only where crimes (1) are universally condemned by the community of nations, and (2) by their nature occur either outside of a State or where there is no State capable of punishing, or competent to punish, the crime (as in a time of war).
Unlike those offenses supporting universal jurisdiction under customary international law – that is, piracy, war crimes, and crimes against humanity – that now have fairly precise definitions and that have achieved universal condemnation, “terrorism” is a term as loosely deployed as it is powerfully charged … Indeed, the nations of the world are so divisively split on the legitimacy of such aggression as to make it impossible to pinpoint an area of harmony or consensus.
We regrettably are no closer now than eighteen years ago to an international consensus on the definition of terrorism or even its proscription. We thus conclude that … terrorism – unlike piracy, war crimes, and crimes against humanity – does not provide a basis for universal jurisdiction. 
United States, Court of Appeals, Second Circuit, Yousef case, Judgment, 4 April 2003.