Can an American be tried before American courts for speeding on the roads of France? When considering whether someone can be convicted, it is necessary to consider not only the conduct in question, but also which courts have jurisdiction. The most common basis of jurisdiction is territorial (i.e., the courts of the place where the action took place), but some legal systems, mainly civil law ones, also recognize jurisdiction based on nationality (i.e., French courts can try French citizens in some cases for criminal conduct outside France). International law also permits a State, in some circumstances, to exercise criminal jurisdiction on other bases. In some cases, the courts of any State may try an individual. This is called universal jurisdiction.

In October 1998, Gen. August Pinochet, the former Chilean dictator, was arrested by British authorities at the request of a Spanish prosecutor. This case may potentially say important things about the scope of universal jurisdiction, but at this writing, the outcome is unknown.

Only the most serious offences are, in international law, subject to universal jurisdiction. A State has primary jurisdiction over these offenses, but whether or not an individual will be tried depends, among other things, on whether the domestic law of the State allows for trial of such crimes. The most serious offenses subject to universal jurisdiction include serious violations of the laws and customs of war, crimes against humanity, and, since the ruling of the International Criminal Tribunal for the Former Yugoslavia (ICTY) in the case of Tadic, violations of Article 3 common to the four Geneva Conventions of 1949, applicable in noninternational armed conflicts.

In addition, certain treaties provide for universal jurisdiction, such as the UN Convention against Torture. Surprisingly, the Genocide Convention is not in this list, though any State may assert universal jurisdiction. It provides for territorial jurisdiction or jurisdiction to be exercised by an international penal tribunal. Generally, treaties which provide for universal jurisdiction require the State to try the suspect or to extradite him/her to stand trial elsewhere.

One category of behavior is subject to a special regime. Grave breaches of the Geneva Conventions 1949 and Additional Protocol I of 1977 are defined within the treaties and can only occur in international armed conflicts. Every State bound by the treaties is under the legal obligation to search for and prosecute those in their territory suspected of having committed grave breaches, irrespective of the nationality of the suspect or victim or the place where the act was allegedly committed. The State may hand the suspect over to another State or an international tribunal for trial. Where domestic law does not allow for the exercise of universal jurisdiction, a State must introduce the necessary domestic legislative provisions before it can do so. That is not enough; the State must actually exercise jurisdiction, unless it hands over the suspect to another country or international tribunal.

(See civilian immunity; international vs. internal armed conflict;
protected persons.)