Prior to the start of Operation Barbarossa, Rosenberg included the ethnically mainly Turkic and Muslim areas of the USSR in Central Asia in his plans for the future establishment of German supremacy in the remnants of the Soviet Union due to their historical antagonism to the extension of Russian control over the area, in spite of his doubts that German conquests would reach that far east.[4] His original proposal entailed the creation of a string of "de-Russified" and German-friendly suzerainties — likely to be someday linked to the Third Reich by either or both the planned Breitspurbahn three-meter rail gauge Nazi heavy rail network and the easternmost extensions of the Reichsautobahn divided highway system — around the Russian "core area" of Muscovy, which was to be deprived of its access to the Baltic and Black Seas. These entities were Greater Finland, the Baltic region, White Ruthenia (Belarus), Greater Ukraine, Greater Caucasia, Turkestan, Idel-Ural, and Siberia, while a stretch of territory on the western frontier with Germany was to become either part of it or otherwise be under its direct control.[4]