Maria Velikonja, Author
For more than four decades, I have worked in the fields of law enforcement, international criminal law, and human rights. As a former prosecutor, FBI Special Agent, FBI Assistant General Counsel, war crimes investigator at the International Criminal Tribunal for the former Yugoslavia (ICTY) during the 1990s, consultant, and now writer, I have devoted my career to the pursuit of evidence, the application of law, and the principle that justice must rest upon individual responsibility rather than collective blame. During the wars in the former Yugoslavia, I investigated allegations of war crimes and crimes against humanity, interviewed victims and witnesses, and helped develop international investigative and legal standards. Those experiences taught me that historical narratives are often shaped by politics, while legal conclusions must be based on facts, evidence, and established principles of international law.
My current work applies those same principles to the history of Slovenia during and immediately after the Second World War. For decades, many of the legal issues surrounding the conflict have been discussed primarily through political or ideological perspectives rather than objective legal analysis. My goal in writing the Legal Concept Papers series is not to defend or condemn any particular group, but to examine the legal status of the various military and political organizations, the conduct of individuals, and the obligations imposed by international humanitarian law both as it existed at the time, and how it would be viewed today. By applying consistent legal standards developed through the Hague Regulations, the Geneva Conventions, the Nuremberg trials, and modern international criminal jurisprudence, I hope to contribute to a more accurate understanding of this difficult period—one grounded in evidence, legal reasoning, and the fundamental principle that responsibility for crimes must always be determined individually rather than collectively.
The ICTY Laid the Foundation for Modern International Law
I worked at the ICTY from 1994 to 1997, which was foundational for the development of modern international criminal law. Although the International Criminal Tribunal for the former Yugoslavia had been established in 1993, it was during these early years that the Tribunal began defining the legal principles that now form the basis of much of international criminal jurisprudence. Through its early judgments and interlocutory decisions, the ICTY clarified the law governing war crimes, crimes against humanity, command responsibility, individual criminal responsibility, and the protection of civilians. Many of these principles were later incorporated into the 1998 Rome Statute of the International Criminal Court and have influenced national war crimes prosecutions around the world.
1. Individual Criminal Responsibility
One of the ICTY’s most important contributions was reaffirming that criminal responsibility is individual rather than collective. The Tribunal repeatedly emphasized that guilt cannot be based solely on membership in an army, political party, ethnic group, or government. Instead, prosecutors must prove each accused person’s own criminal conduct, whether by direct participation, ordering crimes, planning, instigating, aiding and abetting, or through recognized forms of command responsibility.
This principle represented a significant departure from approaches that equated group membership with criminality. It reinforced the Nuremberg principle that organizations may provide context, but criminal liability attaches only to individuals who personally bear responsibility for criminal acts.
2. Crimes Against Humanity During Internal Armed Conflicts
Prior to the ICTY, crimes against humanity had largely been associated with international armed conflicts. In its early jurisprudence—particularly the landmark Tadić decisions—the Tribunal confirmed that crimes against humanity could also occur during internal (non-international) armed conflicts.
This was an important development because many of the conflicts in the former Yugoslavia involved civil wars or mixed internal and international conflicts. The Tribunal focused on whether prohibited acts formed part of a widespread or systematic attack against a civilian population rather than on the formal classification of the conflict.
3. The Expansion of Common Article 3
Perhaps the Tribunal’s most influential contribution came in the 1995 Appeals Chamber Decision on Jurisdiction in Prosecutor v. Tadić. The Appeals Chamber held that many customary rules governing the conduct of hostilities apply equally to non-international armed conflicts.
This decision significantly expanded the practical importance of Common Article 3 of the Geneva Conventions, recognizing that fundamental humanitarian protections apply regardless of whether a conflict is international or internal. The ruling became one of the cornerstones of modern international humanitarian law.
4. Definition of Armed Conflict
The ICTY provided one of the most frequently cited definitions of armed conflict:
“An armed conflict exists whenever there is a resort to armed force between States or protracted armed violence between governmental authorities and organized armed groups or between such groups within a State.”
This definition has been cited repeatedly by later international courts, national courts, military manuals, and scholars.
5. Protection of Persons Hors de Combat
The Tribunal emphasized that once combatants surrender, are captured, or are otherwise rendered incapable of fighting, they become hors de combat and must be protected.
The unlawful killing of prisoners or detainees therefore constitutes a grave violation of international humanitarian law regardless of the victims’ prior military affiliation.
This principle has particular significance for analyses of post-conflict executions, where the legal status of surrendered prisoners becomes central.
6. Command Responsibility
Although command responsibility had existed since Nuremberg, the ICTY substantially clarified its modern application.
The Tribunal explained that military commanders and civilian superiors may incur criminal responsibility when:
–they had effective control over subordinates;
–they knew or had reason to know crimes were being committed; and
–they failed to prevent the crimes or punish those responsible.
The ICTY’s early jurisprudence refined these elements and influenced later international tribunals and the Rome Statute.
7. Sexual Violence as an International Crime
The ICTY began recognizing rape and other forms of sexual violence as serious violations of international law rather than incidental consequences of war.
Although the landmark Furundžija and Kunarac judgments came slightly later, investigations initiated during 1994–1997 helped establish the legal framework that ultimately recognized rape as:
–a war crime,
–a crime against humanity,
–and, under certain circumstances, an act of genocide.
This represented one of the Tribunal’s most enduring contributions. I was the first Team Leader of the sexual assault investigations team at the ICTY, which began in 1995.
8. Superior Orders Are Not a Complete Defense
The ICTY reaffirmed the principle established at Nuremberg that obeying superior orders does not automatically relieve an accused of criminal responsibility.
Orders may be considered in mitigation of punishment, but individuals remain responsible for manifestly unlawful acts such as murder, torture, or execution of prisoners.
9. Fair Trial Guarantees
From its inception, the ICTY emphasized that even persons accused of the gravest international crimes retain fundamental procedural rights.
These included:
–the presumption of innocence;
–proof beyond a reasonable doubt;
–the right to counsel;
–the right to confront witnesses;
–protection against self-incrimination;
–judicial independence;
–public trials;
–appellate review.
The Tribunal sought to demonstrate that international justice must itself adhere to the rule of law.
10. Rules of the Road
Although not part of the Tribunal’s formal jurisprudence, one of the ICTY’s most innovative practical initiatives during this period was the development of the Rules of the Road procedure. This mechanism was designed to prevent arbitrary or politically motivated arrests in Bosnia and Herzegovina after the Dayton Peace Agreement. Our team was very involved in developing this initiative.
Under the Rules of the Road, local authorities could not arrest or indict suspects for serious violations of international humanitarian law unless ICTY prosecutors first reviewed the evidence and concluded that it met an appropriate evidentiary standard. This process promoted consistent legal standards, discouraged politically motivated prosecutions, and strengthened confidence in domestic judicial institutions. The system became an important bridge between international and domestic accountability efforts.
11. Judicial Recognition of Customary International Law
The ICTY frequently relied upon customary international law, not merely treaty law.
The Tribunal demonstrated that international criminal law develops through:
–widespread State practice;
–opinio juris;
–prior international judgments;
–military manuals;
–national legislation;
–scholarly authority.
This methodology has since become standard in international criminal adjudication.
Legacy
The ICTY’s work between 1994 and 1997 transformed international criminal law from a largely dormant field into a functioning judicial system. The Tribunal clarified the legal definitions of armed conflict, crimes against humanity, individual criminal responsibility, command responsibility, and the protection of civilians and prisoners. It also reinforced the principle that accountability is based on proven individual conduct rather than collective guilt. These early decisions laid much of the doctrinal foundation for the Rome Statute, subsequent international tribunals, hybrid courts, and domestic war crimes prosecutions worldwide.