International zone

An international zone is a type of extraterritoriality governed by international law, or similar treaty between two or more nations. The term can also refer to the areas of international airports outside customs and immigration controls. These areas often contain duty-free shopping, but they are not extraterritorial. In areas of conflict there may be international zones called green zones that form protective enclaves to keep diplomats safe. Countries in conflict may also have international zones separating each other.

Iraq has its international zone around the Republican Palace in central Baghdad in a crook of the Tigris River. This area was and still is the heavily fortified headquarters for the coalition and Iraqi Reconstruction Ministries. The official name started as the "Green Zone" but was later changed to the "International Zone" in June 2004 with the return of sovereignty to the Iraqi people.

French, British, American and Soviet troops divided Vienna into four zones, and a small international zone of the historical center of Vienna was governed in rotation by troops of those countries

The international zone in an international airport is the area where arriving international passengers have not formally entered the country by clearing arrival customs and immigration controls, and departing passengers have formally exited the country by clearing exit immigration control.

Transit passengers can take connecting international flights in the international zone without clearing customs and immigration controls, and in most cases do not require a visa. Some countries, however, require passengers of certain nationalities to hold a direct airside transit visa even when they would not need to pass through border controls. A major exception is the United States, where all passengers arriving on international flights are subject to customs and immigration inspections. Hence, transiting at a U.S. airport require at least a C-1 transit visa, or a travel authorization for Visa Waiver Program (VWP) travelers.

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