Should Any State Be Able to Prosecute War Crimes Regardless of Where They Occurred?

Jurisdiction: International LawResearch Type: Doctrinal AnalysisAudience: Practicing Lawyers & Legal ProfessionalsDate: May 2026

I. Introduction: The Doctrine and Its Contemporary Relevance

Universal jurisdiction is a principle of international law that permits — and in some formulations obliges — a state to assert criminal jurisdiction over individuals accused of certain grave offences, irrespective of the nationality of the offender or victim, and regardless of where the conduct occurred. The doctrine rests on the premise that some crimes are so egregious in nature — genocide, war crimes, crimes against humanity, torture, and piracy — that they offend the entire international community and therefore warrant prosecution by any state that obtains custody of the accused.

Current Relevance in Practice: The doctrine has experienced a marked revival since the 1990s, propelled by three structural developments:

• Post-Cold War accountability architecture: The establishment of the International Criminal Tribunals for the former Yugoslavia (ICTY) and Rwanda (ICTR), followed by the Rome Statute of the International Criminal Court (ICC) in 1998, normalised the idea that individuals — including heads of state — bear direct criminal responsibility under international law.
• The Pinochet litigation (1998–1999): The House of Lords’ ruling that former Chilean dictator Augusto Pinochet was not immune from extradition to Spain for acts of torture conducted in Chile fundamentally recalibrated state practice on universal jurisdiction.

Ongoing impunity gaps: Where the ICC lacks jurisdiction — particularly over non-State parties such as the United States, Russia, China, and Israel — national courts operating universal jurisdiction statutes represent the primary accountability mechanism for systemic atrocities.

KEY QUESTION

Can — or should — any sovereign state assert criminal jurisdiction over war crimes committed entirely outside its territory, by and against foreign nationals, with no nexus to the forum state?

II. Statutory and Treaty Framework

A. Customary International Law Foundations

The bedrock of universal jurisdiction lies in customary international law. The Princeton Principles on Universal Jurisdiction (2001), while non-binding, represent an authoritative scholarly articulation of state practice and opinio juris, defining serious crimes under international law as a predicate for universal jurisdiction.

B. Key Treaty Instruments

1. The Geneva Conventions (1949) and Additional Protocols

• Common Article 3 and Article 49/50/129/146 of GC I–IV impose on all High Contracting Parties an obligation to search for, and either prosecute or extradite (aut dedere aut judicare), persons suspected of grave breaches — wilful killing, torture, unlawful deportation, and taking of hostages, among others.
• Grave breaches provisions create arguably the strongest treaty-based mandate for universal jurisdiction in the war crimes context.
• Additional Protocol I (1977), Article 88 reinforces cooperative obligations in prosecution of grave breaches.

2. The Rome Statute of the International Criminal Court (1998)

• Articles 5–8bis define the substantive crimes within ICC jurisdiction, serving as the most widely accepted codification of war crimes under international law.
• The Rome Statute operates on a complementarity principle (Article 17): the ICC defers to national jurisdictions that are willing and able to prosecute, effectively incentivising States Parties to maintain robust domestic universal jurisdiction legislation.
• Significantly, the Rome Statute does not itself confer universal jurisdiction on national courts; it is the Geneva Conventions and customary law that undergird national legislative competence.

3. The UN Convention Against Torture (UNCAT, 1984)

• Article 5(2) requires each State Party to establish jurisdiction over torture offences when the alleged offender is present in its territory — the classic formula for custodial universal jurisdiction.
• UNCAT was the operative treaty framework in the Pinochet proceedings and remains central to contemporary extradition and prosecution disputes.

4. The Convention on the Prevention and Punishment of the Crime of Genocide (1948)

• While Article VI technically limits primary jurisdiction to the territorial state or an international tribunal, Article I — the obligation to prevent and punish — has been read by scholars and some courts as consistent with universal jurisdiction for genocide.
• [VERIFY CITATION] — See ICJ, Bosnia v. Serbia (2007) on obligations to prevent and punish.

C. Notable Domestic Legislative Frameworks

Jurisdiction	Key Legislation	Scope / Notes
Belgium	Act on Grave Breaches of IHL (1993, as amended 2003)	Initially broadest universal jurisdiction statute; severely curtailed after diplomatic pressure (Sharon/Yasser Arafat complaints)
Spain	Organic Law of the Judiciary, Art. 23(4); amended 2009 and 2014	Progressive restriction requiring Spanish victim link or suspect presence after 2009 and 2014 amendments
Germany	Code of Crimes Against International Law (Völkerstrafgesetzbuch – VStGB, 2002)	Robust statute; basis for prosecution of Syrian officials (Koblenz trials, 2021)
United Kingdom	Geneva Conventions Act 1957; International Criminal Court Act 2001	Jurisdiction for grave breaches and ICC crimes; requires consent of Attorney General for prosecution
France	Code of Criminal Procedure, Art. 689-1 et seq.; Act of 9 August 2010	Residual requirements of habitual residence or presence of suspect

III. Landmark Judicial Precedents

The following cases represent the pivotal jurisprudential milestones in the development of universal jurisdiction for war crimes. They are presented in doctrinal rather than strictly chronological sequence to illuminate thematic threads.

R v. Bow Street Metropolitan Stipendiary Magistrate, ex parte Pinochet (No. 3)  |  1999  |  UK House of Lords
Core Legal Question	Whether a former head of state could claim immunity ratione materiae in respect of acts of torture committed during his tenure, so as to defeat an extradition request based on universal jurisdiction under UNCAT.
Ratio Decidendi	A majority of five Law Lords held that, after the UK’s ratification of UNCAT in 1988, Pinochet could not claim functional immunity for acts of torture as those acts could not constitute functions of a head of state under a treaty that universally criminalised such conduct. The principle that international crimes strip the perpetrator of official immunity — at least for the purposes of extradition — was firmly established.
Practical Implication	Establishes that immunity ratione materiae does not apply to jus cogens crimes such as torture and, by extension, war crimes. Practitioners arguing for or against extradition in universal jurisdiction cases must squarely address Pinochet when immunity defences are raised by or on behalf of former officials.

Arrest Warrant of 11 April 2000 (Democratic Republic of Congo v. Belgium)  |  2002  |  International Court of Justice
Core Legal Question	Whether Belgium’s issuance of an international arrest warrant against the sitting DRC Foreign Minister, for grave breaches of the Geneva Conventions and crimes against humanity, violated the DRC’s sovereignty and the incumbent minister’s immunity under customary international law.
Ratio Decidendi	The ICJ held that Belgium had violated the DRC’s sovereignty by failing to respect the absolute immunity of a sitting Foreign Minister under customary international law. Crucially, the Court did not rule on whether Belgium’s universal jurisdiction legislation was lawful per se — the majority expressly declined to address the question of universal jurisdiction in abstentia. Separate and dissenting opinions (Judges Higgins, Kooijmans, Buergenthal; Judge van den Wyngaert) offered important analyses of the permissibility of universal jurisdiction.
Practical Implication	Immunity of sitting high officials (heads of state, heads of government, foreign ministers) operates as a procedural bar to prosecution even for war crimes — unless before an international tribunal or after loss of office. This is an essential threshold issue in any universal jurisdiction action. The case underscores the importance of timing: a suspect who retains serving status cannot be arraigned in foreign courts regardless of the gravity of the alleged crimes. [VERIFY CITATION — full citation: ICJ Reports 2002, p. 3]

Prosecutor v. Tadic (Jurisdiction Decision)  |  1995  |  International Criminal Tribunal for the Former Yugoslavia (ICTY), Appeals Chamber
Core Legal Question	Whether the ICTY had jurisdiction over violations of the laws or customs of war committed in the context of an internal (non-international) armed conflict, and whether customary international law so permitted.
Ratio Decidendi	The Appeals Chamber held that the traditional distinction between international and non-international armed conflicts, for the purposes of individual criminal responsibility, had been substantially eroded in customary international law. Serious violations of IHL committed in internal armed conflicts attract individual criminal responsibility under customary law. This reasoning informed subsequent articulations of war crimes in the Rome Statute and directly underpins universal jurisdiction exercises over crimes committed in civil wars.
Practical Implication	For practitioners, Tadic is authoritative for the proposition that universal jurisdiction is not limited to inter-state conflicts. Atrocities committed in intra-state contexts — Syria, Yemen, Myanmar — are susceptible to prosecution in domestic courts exercising universal jurisdiction. The characterisation of an armed conflict as international or non-international remains, however, a live issue in domestic proceedings and must be carefully assessed on the facts. [VERIFY CITATION — ICTY Appeals Chamber, Case No. IT-94-1-AR72, 2 October 1995]

Germany v. Anwar R. and Eyad A. (Koblenz Trial — Syrian Torture / War Crimes)  |  2021–2022  |  Higher Regional Court (Oberlandesgericht) Koblenz, Germany
Core Legal Question	Whether former Syrian intelligence officers could be prosecuted in Germany under the VStGB for crimes against humanity (including torture, murder, and sexual violence) committed in Syria against Syrian nationals, with no direct German nexus beyond the accused’s presence in Germany as asylum seekers.
Ratio Decidendi	The Koblenz Court convicted Anwar R. of crimes against humanity as a co-perpetrator under the VStGB, relying expressly on Germany’s universal jurisdiction statute. The court found that the presence of the accused in Germany following their flight as refugees was sufficient to ground jurisdiction. The judgment represents the first instance anywhere in the world of a verdict relating to state-sponsored torture and murder by the Syrian government.
Practical Implication	Koblenz is the most significant domestic universal jurisdiction conviction in the contemporary era. It demonstrates that: (a) presence-based universal jurisdiction (suspect present in the forum state) is a workable and legally sound basis for prosecution; (b) victim testimony gathered by civil society organisations can support criminal proceedings; and (c) asylum and refugee flows can bring perpetrators within reach of foreign courts. Practitioners in jurisdictions with comparable statutes should consider Koblenz as a persuasive template for case-building. [VERIFY CITATION — OLG Koblenz, 3 StE 4/21, judgment of 13 January 2022]

Questions Relating to the Obligation to Prosecute or Extradite (Belgium v. Senegal)  |  2012  |  International Court of Justice
Core Legal Question	Whether Senegal breached its obligations under UNCAT and customary international law by failing to prosecute former Chadian president Hissène Habré for acts of torture and crimes against humanity, or to extradite him to Belgium.
Ratio Decidendi	The ICJ found Senegal had breached Article 7(1) of UNCAT by failing to submit the case for prosecution without undue delay. The Court affirmed that the obligation aut dedere aut judicare is an obligation of result under UNCAT, not merely one of means. Critically, the Court held that all States Parties to UNCAT have a legal interest in compliance with that obligation — establishing standing for any State Party to invoke responsibility, even without a specific bilateral connection to the offences.
Practical Implication	This case has two vital practical implications: (1) States possessing custody of an alleged war crimes perpetrator are under a non-derogable legal obligation to prosecute or extradite; delay or inaction is itself a breach of international law, not merely a political failing; (2) the judgment confirms erga omnes partes obligations — meaning legal practitioners representing victim states or NGOs may credibly invoke third-state standing to challenge prosecutorial inaction. [VERIFY CITATION — ICJ Reports 2012, p. 422]

IV. Critical Analysis: Gaps, Tensions, and Reform Imperatives

A. The Immunity Conundrum: Sitting Officials and the Accountability Gap

The tension between immunity of serving officials and accountability for jus cogens crimes represents the most structurally unresolved fault line in the doctrine. The ICJ in Arrest Warrant confirmed that serving foreign ministers are absolutely immune before domestic courts, even for war crimes. This creates an accountability gap that universal jurisdiction — as currently practised — cannot bridge: the worst ongoing atrocities are often ordered by sitting heads of state or government officials who enjoy precisely this immunity.

• Reform Need: A principled exception to head-of-state immunity before domestic courts for jus cogens crimes would align immunity law with the normative framework of international criminal law. No such exception has crystallised in customary law despite significant academic support.

B. The Nexus Debate: Absolute vs. Conditional Universal Jurisdiction

A substantial controversy persists between advocates of absolute universal jurisdiction (prosecution without any nexus to the forum state) and proponents of conditional universal jurisdiction (requiring at minimum the suspect’s presence in, or another connection to, the forum state). The African Union has consistently criticised the former as a form of neo-colonial interference, particularly targeting European states’ prosecution of African leaders.

• Practical Consequence: Belgium’s retreat from its 1993 statute following intense diplomatic pressure from the United States, Israel, and the AU illustrates the political fragility of absolute universal jurisdiction, regardless of its doctrinal validity.
• Reform Trajectory: State practice increasingly favours presence-based universal jurisdiction (the ‘Koblenz model’) as a politically sustainable middle ground. However, in-absentia proceedings — as permitted under certain conditions in French law — remain contested.

C. Selectivity and Geopolitical Double Standards

Critics — including many Global South scholars and the AU — argue that universal jurisdiction is selectively deployed against weaker states while the crimes of powerful nations and their allies escape scrutiny. The failure of any European state to initiate universal jurisdiction proceedings against senior US officials for documented torture at Abu Ghraib or CIA black sites is frequently cited as evidence of structural bias.

• Doctrinal Response: International law provides no principled basis for selective non-prosecution; the aut dedere aut judicare obligation is non-discriminatory. However, prosecutorial discretion remains a domestic matter, and political considerations inevitably operate in practice.

D. Evidentiary and Procedural Challenges

Universal jurisdiction trials present unique evidentiary difficulties: witnesses are typically in third countries, often in conflict zones; documents are inaccessible; chain-of-custody for digital evidence may be legally uncertain; and the accused may have little incentive to cooperate. The Koblenz proceedings required years of preparatory work by Syrian civil society organisations and relied heavily on testimonial evidence from refugees.

• Legislative Gap: Most domestic legal systems lack purpose-built procedural frameworks for international crimes trials, creating ad hoc adaptations of evidence law that risk inconsistency and appellate vulnerability.

E. The Role of Civil Society and Its Legal Limits

Non-governmental organisations — particularly the European Center for Constitutional and Human Rights (ECCHR) and the Centre for Justice and Accountability — have driven universal jurisdiction litigation by filing criminal complaints, gathering evidence, and providing legal representation to survivors. This represents a structural feature of the accountability ecosystem that sits outside traditional state-centric models.

• Unresolved Question: The legal standing of NGOs and victim coalitions varies across domestic legal systems. A comparative analysis of standing rules would benefit practitioners considering multi-jurisdictional litigation strategies.

V. Practice Notes: Actionable Guidance for Legal Professionals

The following notes distil the preceding analysis into concrete guidance for practitioners advising clients on universal jurisdiction matters.

Conduct a Comprehensive Jurisdictional Mapping Before Any FilingBefore initiating or defending universal jurisdiction proceedings, practitioners must audit: (a) the applicable domestic statute and any nexus requirements (presence, nationality, habitual residence); (b) whether the forum state has ratified the relevant treaty instruments (Geneva Conventions, UNCAT, Rome Statute); (c) the status of the accused — sitting or former official — and the applicable immunity regime; and (d) whether the Attorney General, Director of Public Prosecutions, or equivalent consent mechanism applies. The failure to address immunity at the outset is the most common — and most consequential — procedural error in this area of practice.

Build an Evidentiary Architecture Compatible with Both Domestic and International StandardsUniversal jurisdiction cases are won or lost on evidence. Practitioners must: (a) advise clients and civil society partners on chain-of-custody requirements for digital evidence — open-source intelligence (OSINT), satellite imagery, and intercepted communications face different authentication standards across jurisdictions; (b) ensure witness statements are taken in a manner compatible with the forum’s hearsay and credibility rules; (c) consider whether evidence collected for ICC or UN investigative bodies is transferable to domestic proceedings without breaching confidentiality obligations; and (d) document command structure and superior responsibility chains with sufficient granularity to survive a motion to dismiss for failure to establish individual criminal responsibility. The Koblenz prosecution team’s use of structured NGO-gathered testimony provides a replicable model.

Anticipate and Counter the Political and Diplomatic DimensionsUniversal jurisdiction litigation is never purely legal. Practitioners must advise clients that: (a) charges against senior foreign officials will likely trigger diplomatic protests and may result in legislative reform restricting the forum state’s jurisdiction (as occurred in Belgium and Spain); (b) the forum state’s government may exercise prosecutorial discretion to discontinue proceedings for political reasons — practitioners should explore whether judicial review of such decisions is available; (c) coordination with proceedings at the ICC, regional human rights bodies, or UN mechanisms can provide political insulation and evidentiary synergies; and (d) public interest litigation strategy — including strategic media engagement and coalition-building with diaspora communities — materially affects political sustainability of proceedings. The intersection of law and geopolitics in this area requires practitioners to function as both legal technicians and strategic counsel.

VI. Conclusion

Universal jurisdiction for war crimes is simultaneously a legal doctrine of compelling normative logic and a mechanism of fragile political sustainability. The doctrinal case is strong: grave breaches of IHL injure the international community as a whole, and the aut dedere aut judicare obligation imposes affirmative duties on all States. The Koblenz convictions demonstrate that the doctrine is operationally viable when domestic institutions possess the will, resources, and appropriate legislative framework to pursue accountability.

However, the immunity gap, geopolitical selectivity, and structural evidentiary challenges mean that universal jurisdiction functions as a partial, not a systemic, accountability remedy. Comprehensive reform — including a jus cogens exception to head-of-state immunity, harmonisation of nexus requirements, and purpose-built procedural frameworks for international crimes trials — remains an unfinished legislative agenda at both national and international levels.

For the practising lawyer, this domain rewards meticulous statutory analysis, multi-jurisdictional strategy, and an acute awareness that legal proceedings in this area are inherently political acts with consequences that extend well beyond the courtroom.

DisclaimerThis brief is intended as a high-level analytical overview for legal professionals and does not constitute legal advice. All case citations marked [VERIFY CITATION] should be independently verified before reliance in proceedings. The law in this area is rapidly evolving; practitioners should consult the most current domestic legislation and international instruments applicable to their specific jurisdiction.