18 U.S. Code § 2441 - War crimes
(a) Offense.â
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.â
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).
(c) Definition.âAs used in this section the term âwar crimeâ means any conductâ
(1) defined as a grave breach in any of the international conventions signed at Geneva 12 August 1949, or any protocol to such convention to which the United States is a party;
(2) prohibited by Article 23, 25, 27, or 28 of the Annex to the Hague Convention IV, Respecting the Laws and Customs of War on Land, signed 18 October 1907;
(3) which constitutes a grave breach of common Article 3 (as defined in subsection (d)) when committed in the context of and in association with an armed conflict not of an international character; or
(4) of a person who, in relation to an armed conflict and contrary to the provisions of the Protocol on Prohibitions or Restrictions on the Use of Mines, Booby-Traps and Other Devices as amended at Geneva on 3 May 1996 (Protocol II as amended on 3 May 1996), when the United States is a party to such Protocol, willfully kills or causes serious injury to civilians.
(d) Common Article 3 Violations.â
(1) Prohibited conduct.âIn subsection (c)(3), the term âgrave breach of common Article 3â means any conduct (such conduct constituting a grave breach of common Article 3 of the international conventions done at Geneva August 12, 1949), as follows:
(A) Torture.â
The act of a person who commits, or conspires or attempts to commit, an act specifically intended to inflict severe physical or mental pain or suffering (other than pain or suffering incidental to lawful sanctions) upon another person within his custody or physical control for the purpose of obtaining information or a confession, punishment, intimidation, coercion, or any reason based on discrimination of any kind.
(B) Cruel or inhuman treatment.â
The act of a person who commits, or conspires or attempts to commit, an act intended to inflict severe or serious physical or mental pain or suffering (other than pain or suffering incidental to lawful sanctions), including serious physical abuse, upon another within his custody or control.
(C) Performing biological experiments.â
The act of a person who subjects, or conspires or attempts to subject, one or more persons within his custody or physical control to biological experiments without a legitimate medical or dental purpose and in so doing endangers the body or health of such person or persons.
(D) Murder.â
The act of a person who intentionally kills, or conspires or attempts to kill, or kills whether intentionally or unintentionally in the course of committing any other offense under this subsection, one or more persons taking no active part in the hostilities, including those placed out of combat by sickness, wounds, detention, or any other cause.
(E) Mutilation or maiming.â
The act of a person who intentionally injures, or conspires or attempts to injure, or injures whether intentionally or unintentionally in the course of committing any other offense under this subsection, one or more persons taking no active part in the hostilities, including those placed out of combat by sickness, wounds, detention, or any other cause, by disfiguring the person or persons by any mutilation thereof or by permanently disabling any member, limb, or organ of his body, without any legitimate medical or dental purpose.
(F) Intentionally causing serious bodily injury.â
The act of a person who intentionally causes, or conspires or attempts to cause, serious bodily injury to one or more persons, including lawful combatants, in violation of the law of war.
(G) Rape.â
The act of a person who forcibly or with coercion or threat of force wrongfully invades, or conspires or attempts to invade, the body of a person by penetrating, however slightly, the anal or genital opening of the victim with any part of the body of the accused, or with any foreign object.
(H) Sexual assault or abuse.â
The act of a person who forcibly or with coercion or threat of force engages, or conspires or attempts to engage, in sexual contact with one or more persons, or causes, or conspires or attempts to cause, one or more persons to engage in sexual contact.
https://www.law.cornell.edu/uscode/text/18/2441