How Universal Jurisdiction and Jus Cogens Allow States to Prosecute International Crimes

On October 16, 1998, British police entered a London clinic and arrested Augusto Pinochet, the former president of Chile, acting on a warrant issued by a Spanish magistrate. The arrest did not involve crimes committed in Spain or against Spanish citizens. Instead, it relied on a legal architecture designed to ensure that the perpetrators of the most severe atrocities cannot find safe harbor simply by crossing a border.[5]

This framework operates outside the standard rules of territorial sovereignty. In typical criminal law, a state only prosecutes offenses committed on its own soil or by its own citizens. International criminal law bypasses this limitation through a combination of three distinct but interlocking concepts: the peremptory norms known as jus cogens, the obligation to extradite or prosecute (aut dedere aut judicare), and the mechanism of universal jurisdiction.[1][2][5]

The foundation of this system is the jus cogens principle. Defined formally in Article 53 of the 1969 Vienna Convention on the Law of Treaties, a jus cogens norm is "a norm accepted and recognized by the international community of States as a whole as a norm from which no derogation is permitted."[2]

In practice, this means certain acts—specifically genocide, torture, slavery, and wars of aggression—are universally prohibited. No treaty, domestic law, or political agreement can override a jus cogens prohibition. As outlined in the Duke Law Scholarship Repository's analysis of international crimes, these norms generate what are known as obligatio erga omnes—obligations owed to the international community as a whole, rather than to any single nation.[2]

Because the prohibition is absolute and owed to all, the violation of a jus cogens norm theoretically gives every state a legal interest in seeing the perpetrator punished. However, a theoretical interest does not automatically translate into a courtroom trial. That transition requires a procedural mechanism to compel action.[2][6]

This is where the aut dedere aut judicare rule enters the framework. Translated from Latin as "extradite or prosecute," this principle requires a state holding a suspected offender to either try them in its own domestic courts or hand them over to a jurisdiction willing to do so.[1]

The Oxford Public International Law encyclopedia notes that this rule is heavily codified in modern treaty law. For example, the 1984 United Nations Convention against Torture, which currently has 162 state parties, explicitly includes an aut dedere aut judicare provision. If a suspected torturer is found in the territory of a member state, that state is legally bound to act, regardless of where the torture occurred.[1]

When a state chooses to prosecute a foreign national for crimes committed abroad against foreign victims, it exercises universal jurisdiction. The International Center for Transitional Justice (ICTJ) defines this as the principle that allows domestic courts to try individuals for grave international crimes even when there is no traditional nexus of territory or nationality.[3]

Universal jurisdiction is distinct from the jurisdiction exercised by international tribunals like the International Criminal Court (ICC), which was established by the 1998 Rome Statute. The ICC is a supranational body of last resort. Universal jurisdiction, by contrast, empowers individual, domestic national courts to act as agents of the international community.[3][4]

The Journal of International Criminal Justice clarifies that this concept is not entirely new. Its origins lie in the 17th-century treatment of piracy. Because pirates operated on the high seas—outside any nation's territorial waters—they were deemed hostis humani generis (enemies of all mankind), allowing any capturing nation to try them.[4]

Following the atrocities of World War II, this logic was expanded. The 1949 Geneva Conventions explicitly mandated that states search for and prosecute those suspected of "grave breaches" of the laws of war, effectively codifying universal jurisdiction for specific war crimes.[5]

Despite its robust theoretical grounding, the actual application of these principles remains highly uneven. The Pardee Atlas Journal of Global Affairs highlights the profound complexity and political friction generated when one state attempts to judge the former officials of another.

"The exercise of universal jurisdiction often collides directly with the principle of state immunity," notes the Factlen Editorial Team in its synthesis of these legal doctrines. "While jus cogens norms theoretically strip away immunity for international crimes, domestic courts are frequently hesitant to prosecute foreign state actors without explicit legislative backing."[6]

This hesitation creates a significant enforcement gap. A state may recognize a jus cogens violation and acknowledge its aut dedere aut judicare treaty obligations, yet still decline to prosecute due to diplomatic pressure, lack of resources, or restrictive domestic laws that require the accused to be physically present in the territory before an investigation can begin.[6]

Recently, however, the doctrine has seen a resurgence in European courts. In 2022, a German court convicted a former Syrian intelligence officer of crimes against humanity, sentencing him to life in prison. The trial relied entirely on universal jurisdiction, as neither the perpetrator nor the victims were German, and the crimes occurred in Damascus.[3][5]

This German conviction demonstrates the practical endpoint of the legal architecture. A jus cogens norm established the absolute prohibition of the crime; the aut dedere aut judicare principle prevented Germany from simply ignoring the suspect's presence; and universal jurisdiction provided the legal authority for a domestic judge in Koblenz to deliver a verdict on atrocities committed 2,000 miles away.[1][2][5]