US and International Criminal Law

Introduction

The United States occupies a complex and often contradictory position in the international criminal law system. As a principal architect of the post-World War II international legal order and a driving force behind the Nuremberg tribunals, the US shaped the foundational doctrines of individual criminal accountability for atrocity crimes. Yet in the decades since, Washington has maintained an ambivalent—and at times openly hostile—relationship with multilateral institutions, most notably the International Criminal Court.

The Nuremberg Legacy and US Leadership

The modern architecture of international criminal law owes its existence in significant measure to American legal innovation. US Supreme Court Justice Robert H. Jackson served as chief prosecutor at Nuremberg, where he articulated the principle that individuals, not merely states, bear responsibility under international law. The Nuremberg Charter’s definitions of crimes against peace, war crimes, and crimes against humanity were profoundly shaped by US legal thinking. The subsequent Einsatzgruppen trial and the Hostages Trial further developed the doctrines of command responsibility and superior orders, both of which remain central to contemporary international criminal practice.

The US also played a pivotal role in the Tokyo Tribunal and, decades later, in the establishment of the International Criminal Tribunal for the former Yugoslavia and the International Criminal Tribunal for Rwanda. American intelligence, forensic expertise, and legal personnel were indispensable to the functioning of both ad hoc tribunals.

Domestic Prosecution of International Crimes

The War Crimes Act of 1996 (18 U.S.C. § 2441) criminalises grave breaches of the Geneva Conventions committed by or against US nationals or members of the US armed forces. The statute was amended by the Military Commissions Act of 2006 to incorporate Common Article 3 violations, following the Supreme Court’s decision in Hamdan v. Rumsfeld (2006), which held that Common Article 3 applied to the conflict with Al-Qaeda.

The Genocide Convention Implementation Act of 1987 (18 U.S.C. § 1091) criminalises genocide as defined in the Convention on the Prevention and Punishment of the Crime of Genocide. The statute applies to conduct within the United States and to conduct by US nationals abroad, but stops short of universal jurisdiction.

The Torture Victim Protection Act (TVPA) of 1991 provides a civil remedy for acts of torture and extrajudicial killing committed under colour of law of any foreign nation. It operates alongside the Alien Tort Statute (ATS) (28 U.S.C. § 1350), which grants federal district courts jurisdiction over civil actions brought by aliens for torts committed in violation of the law of nations. The ATS has been the vehicle for numerous high-profile human rights cases, including Filártiga v. Peña-Irala (1980), in which the Second Circuit held that deliberate torture violates the law of nations, and Sosa v. Alvarez-Machain (2004), which established limits on the recognition of new norms.

The United States and the International Criminal Court

The US signed the Rome Statute in December 2000 under President Clinton but did not submit it for Senate ratification. In May 2002, the Bush administration formally “unsigned” the treaty, signalling a policy of active opposition. The American Service-Members’ Protection Act (ASPA) of 2002, colloquially known as the “Hague Invasion Act,” authorises the President to use “all means necessary and appropriate” to secure the release of US and allied personnel detained by the ICC. ASPA also prohibits US cooperation with the Court and restricts military assistance to states party to the Rome Statute.

The US pursued a strategy of bilateral Article 98 agreements, obtaining commitments from dozens of states not to surrender US nationals to the ICC. These agreements relied on Article 98(2) of the Rome Statute, which prohibits the Court from requesting cooperation that would require a state to act inconsistently with its obligations under international agreements.

The Obama administration adopted a more cooperative posture, providing limited assistance to ICC investigations in Libya and participating as an observer in ICC Assembly of States Parties meetings. The Trump administration reimposed sanctions on ICC personnel investigating US and allied forces in Afghanistan, including Prosecutor Fatou Bensouda. The Biden administration lifted those sanctions while reaffirming US opposition to ICC jurisdiction over non-party states.

Command Responsibility and Military Doctrine

The US military incorporates international humanitarian law principles through the Uniform Code of Military Justice (UCMJ) and the Department of Defense Law of War Manual. The doctrine of command responsibility, established in In re Yamashita (1946), holds commanders criminally liable for failing to prevent or punish atrocities committed by subordinates. This principle was codified in Article 86 of Additional Protocol I and has been applied in US courts-martial and courts of inquiry.

Universal Jurisdiction and US Practice

The US has traditionally been cautious regarding universal jurisdiction, neither broadly adopting it in domestic law nor opposing it in principle in all contexts. US courts have exercised extraterritorial jurisdiction over piracy, hostage-taking, and certain terrorist offences, but Congress has not enacted a general universal jurisdiction statute for international crimes. The approach differs markedly from that of European states such as Belgium, Spain, and Germany, which have exercised universal jurisdiction over genocide and torture.

Conclusion

The United States remains an indispensable actor in international criminal law, both as a normative force and as a practical obstacle to institutional consolidation. Its selective engagement—championing accountability where it aligns with strategic interests while resisting constraints on its own personnel—reflects the persistent tension between sovereignty and supranational justice. Whether the US will re-emerge as a leader in the field or continue as an ambivalent outsider depends on domestic political dynamics and the evolution of the ICC itself.