Border control is the implementation of border controls on travel between Svalbard, which maintains a policy of free migration as a result of the Svalbard Treaty (Norwegian: Svalbard-traktaten; ) and the Schengen Area, which includes the rest of Norway. The Kingdom of Denmark also maintains a complex system of subnational countries with autonomous customs policies, since they aren’t within the European Union like the Danish mainland. These are Greenland () and the Faroe Islands (). These areas do not maintain strict immigration controls with the Schengen Area, but border controls are sporadically enforced for customs purposes. Other examples of effective internal border
Western European Union European Security and Defence Identity (ESDI) within NATO structures. The ESDI was intended as a European 'pillar' within NATO, partly to allow European countries to act militarily where NATO wished not to, and partly to alleviate the United States' financial burden of maintaining military bases in Europe, which it had done since the Cold War. The Berlin agreement allowed European countries (through the WEU) to use NATO assets if it so wished. In 1998 the United Kingdom, which had traditionally opposed the introduction of European autonomous defence capacities, signed the Saint-Malo declaration. This marked a turning point as the declaration