Trans-Siberian Railway imperial collapse, and before the Red Army took control, the Czechs and Slovaks were able to use their organisation and the resources of the railway to establish a temporary zone of control before eventually continuing onwards towards Vladivostok, from where they emigrated back to Czechoslovakia. During World War II, the Trans-Siberian Railway played an important role in the supply of the powers fighting in Europe. During the first two years of the war the USSR had secretly agreed to a neutrality and non-aggression pact with Germany. While Germany's merchant shipping was interdicted by the Western allies, the Trans-Siberian Railway (along
Trans-Mongolian Railway line began in 1947, reaching Ulan Bator from the north in 1950 and the Chinese border in 1955. Before that the only railways in Mongolia had been a line (opened in 1938) connecting the coal mines at Nalaikh to the capital and a Soviet-built freight-only branch (completed in 1939) from Borzya on the Trans-Siberian Railway to Bayantümen, Dornod near Choibalsan in north-eastern Mongolia. Russian Irkutsk State University of Railway Engineering opened its Ulaanbaatar branch in June 2009. The Mongolian Railway company "Mongolyn Tömör Zam" carries 80% of all freight and 30% of all passenger transport within Mongolia. In the aftermath