Georgia is located in the Caucasus region, a transcontinental zone between Europe and Asia, and is surrounded by powerful neighbors that have controlled part or all of the country throughout much of its history. These include Russia to the north, Turkey to the southwest and Iran to the southeast. Georgia's core is found in the capital city of Tbilisi, where the country's economic, political and demographic resources are concentrated. But because of Georgia's largely mountainous terrain, the country has distinct regional differences and contains various non-Georgian ethnic groups that have traditionally maintained autonomy from Tbilisi. These groups, most notably the Abkhazians and Ossetians to the northwest and north, have posed a separatist problem for the Georgian state. The territories of Abkhazia and South Ossetia established de facto independence from Georgia with the help of Russia in a 2008 war. Because of Georgia's disputes with Russia and its military vulnerability, Tbilisi has sought to integrate with Western blocs like NATO and the European Union. However, Georgia's geographic distance from Europe and its exposure to Russia has made that a difficult prospect. Thus, Tbilisi also seeks supplementary partnerships with countries like Azerbaijan and Turkey.