International law includes a mechanism (called universal jurisdiction) by which states can prosecute individuals for certain without regard to the nationality of the victim and/or the suspect, no matter where the crime occurred. Although it has only become especially relevant in the postwar era, legal precursors have been traced back all the way to the Justinian Code.

Excercising universal jurisdiction is not as simple as a prosecutor merely announcing that he or she is going to prosecute someone, however. First, the state must have enacted a law allowing them to exercise universal jurisdiction. To date, at least 125 states have laws that allow them to claim jurisdiction over at least some crimes.

Legal scholar Kenneth Randall offers five cases under which universal jurisdiction can be exercised. These are: (1)if the crime affects a state directly even if it does not occur directly on their territory; if the (2)perpetrator or the (3)victim is a national of the prosecuting state; (4) if the act seriously affects the security of the prosecuting state; (5) or if the act is universally condemned - e.g., if it's a crime against humanity.

To date, according to Amnesty International, fifteen countries have utilized universal jurisdiction from start to finish (investigation to completed trial). These are: Australia, Austria, Belgium, Canada, Denmark, France, Germany, Israel, Mexico, the Netherlands, Senegal, Spain, Switzerland, the United Kingdom and the United States.

Although it can be used for other purposes, universal jurisdiction exists primarily to prosecute acts that rise to the level of war crimes or crimes against humanity - slavery, piracy and the like.

Universal jurisdiction was most famously exercised for some of the post-World War II trials of Japanese and German war criminals. Both the United States and the United Kingdom cited universal jurisdiction in arguments in some of these trials, including some of the Nuremberg trials. After the U.S. and U.K. backed off on war crimes tribunals at the start of the cold war, Israel picked up the banner of universal jurisdiction, most notably in the Adolf Eichmann case. Additionally, any number of countries have exercised universal jurisdiction over Argentina (for crimes including kidnapping and assassination), Yugoslavia and Rwanda(genocide).

Even more recently, several of head of state have been made the targets of courts using universal jurisdiction, some more effectively than others. Among these are Saddam Hussein, Ariel Sharon and Laurent Kabila.

A good primer on universal jurisdiction can be found at