Extraterritorial jurisdiction

Extraterritorial jurisdiction (ETJ) is the legal ability of a government to exercise authority beyond its normal boundaries.

Any authority can claim ETJ over any external territory they wish. However, for the claim to be effective in the external territory (except by the exercise of force), it must be agreed either with the legal authority in the external territory, or with a legal authority which covers both territories. When unqualified, ETJ usually refers to such an agreed jurisdiction, or it will be called something like "claimed ETJ".

The phrase may also refer to a country's laws extending beyond its boundaries in the sense that they may authorise the courts of that country to enforce their jurisdiction against parties appearing before them in respect of things that they did outside that country. This does not depend on the co-operation of other countries, since the affected people are within the relevant country (or their case is being heard by a court of that country). For example, many countries have laws which give their criminal courts jurisdiction to try prosecutions for piracy or terrorism committed outside their national boundaries. Sometimes such laws only apply to nationals of that country, and sometimes they may apply to anyone.

Diplomatic immunity of foreign embassies and consulates in host countries is governed by the Vienna Convention on Diplomatic Relations and the Vienna Convention on Consular Relations.

Status of Forces Agreements and Visiting Forces Agreements are in effect in many countries that allow visiting forces to exercise exclusive jurisdiction over members of their forces that are stationed in the host country.

Criminal jurisdiction can be of an extraterritorial nature where:

Criminal codes in certain countries assert jurisdiction over crimes committed outside the country:

Many countries have implemented laws which allow their nationals to be prosecuted by their courts for crimes such as war crimes and genocide even when the crime is committed extraterritorially. As well, the Rome Statute of the International Criminal Court has been incorporated into domestic law in many countries to provide for the International Criminal Court to exercise jurisdiction within their borders.

...
Wikipedia