Crimes against humanity are among the most serious crimes of concern to the international community as a whole and are prohibited under customary international law. However, unlike genocide and war crimes, they are not covered by any dedicated global treaty imposing obligations on States to prevent, criminalise, investigate, prosecute and co-operate. The Rome Statute of the International Criminal Court, which contains a definition of crimes against humanity, creates obligations only towards the Court, but not between States Parties.
In recent years, the Parliamentary Assembly has found that crimes against humanity have been or may have been committed in different parts of the world: in the context of the ongoing Russian Federation’s aggression in Ukraine; in Belarus by the Lukashenka regime; in Syria and Iraq by Daesh; and more recently in Iran. Perpetrators of crimes against humanity must be held to account, wherever the crimes were committed.
The United Nations General Assembly has decided to convene a Conference of Plenipotentiaries in 2028 and 2029 to elaborate and conclude a legally binding instrument on crimes against humanity. Its Preparatory Committee met in January 2026 and will meet again in April 2027. Many Council of Europe member States and the European Union are actively participating in this process. If successfully concluded, this new treaty would constitute the first major codification in international criminal law since the adoption of the Rome Statute in 1998.
Eighty years after Nuremberg, crimes against humanity still have no universal treaty of their own. The Assembly, committed to the development of international law, should therefore follow the UN negotiations closely, propose a Council of Europe position in a resolution, and call on all member States and partners to support an ambitious convention that strengthens the effective protection of human rights under international law.