Duty to Prosecute or Extradite: Reflections on the Basis of States' Obligations Stemming from Violations of Jus Cogens Norms

The obligation to prosecute or extradite is a growing sensitive issue in international law. In the recent case Questions Relating to the Obligation to Prosecute or Extradite (Belgium v. Senegal), the International Court of Justice was confronted with determining a breach to the obligation to prosecute or extradite in relation to acts of torture set forth in Article 7(1) of the 1984 UN Convention Against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment.

Departing from this pronouncement, the author inquires whether the obligation to prosecute or extradite correlative to the prohibition of torture can be claimed only pursuant to a treaty norm or by virtue of customary international law alike. Additionally, the author examines what the quid pluris is, in terms of obligations, of defining the prohibition of torture as jus cogens. In an attempt to shed light on these issues, the author will consider fundamentals of international criminal law, in particular whether an obligation to prosecute or extradite is established for certain international crimes which constitute violations of jus cogens norms.