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
Ulan-Ude Okrug. According to the 2010 Census, 404,426 people lived in Ulan-Ude; up from 359,391 recorded in the 2002 Census. In terms of population, it is the third largest city in eastern Siberia. The ethnic makeup of the city's population in 2010: The city is the center of Tibetan Buddhism in Russia and the important Ivolginsky datsan is located from the city. Ulan-Ude is located on the main line (Trans-Siberian line) of the Trans-Siberian Railway between Irkutsk and Chita at the junction of the Trans-Mongolian line (the Trans-Mongolian Railway) which begins at Ulan Ude and continues south through Mongolia to Beijing