Universal jurisdiction is the principle that certain crimes are so grave and threatening to the international order that any state may prosecute them, regardless of where they were committed or the nationality of the offender or victim. Originating with piracy, it now applies mainly to international crimes such as genocide, crimes against humanity, war crimes, and torture, reflecting obligations under customary international law and often limited to violations of jus cogens. The principle is aimed at preventing impunity, as famously articulated in the Eichmann trial (1961). While universal jurisdiction in absentia remains controversial, a less far-reaching form is the aut dedere aut judicare obligation, requiring states to prosecute or extradite offenders found on their territory under specific treaties.