of prime minister Nikola Pašić under King Peter I Karađorđević re-orientated Serbia towards Russia. Serbia was supported by Russia in the economic Pig War (1906–08) with Austria-Hungary. Austria-Hungary annexed Bosnia and Herzegovina in 1908; Russia did not interfere in the Bosnian crisis. The "National Defence" (Narodna Odbrana) organization was founded following the annexation, and sought to liberate Serb territories from Austro-Hungarian rule. World War I One of the factors that led to the beginning of World War I was close bilateral relations between the Kingdom of Serbia and the Russian Empire. While Russia and Serbia were not formally allied, Russia openly sought political and religious influence in Serbia. In May 1914, Serbian politics were polarized between two factions, one headed by the Prime Minister Nikola Pašić, and the other by the radical nationalist chief of Military Intelligence, Colonel Dragutin Dimitrijević, known by his codename Apis. In that month, due to Colonel Dimitrijević's intrigues, King Peter dismissed Pašić's government, but the Russian Minister in Belgrade intervened to have Pašić's government restored. Pašić, though he often talked in public, knew that Serbia was near-bankrupt and, having suffered heavy casualties in the Balkan Wars and in the suppression of an Albanian revolt in Kosovo, needed peace. Since Russia also favoured peace in the Balkans, from the Russian viewpoint it was desirable to keep Pašić in power. However, the Assassination of Archduke Franz Ferdinand led Austria-Hungary to declare war on Serbia during the July Crisis. Russia mobilised its armed forces in late July ostensibly to defend Serbia, but also to maintain status as a Great Power, gain influence in the Balkans and deter Austria-Hungary and Germany. This led Germany to declare war on Russia on 1 August, ultimately expanding the local conflict into a world war. Inter-war period, Russian emigration A few months after the Russian Revolution in November 1917, the Russian Civil War ensued, in which a small number of mercenaries from Yugoslavia fought for both the Russian Whites and the Bolsheviks. After the Civil War ended in 1922 in a Bolshevik victory, relations between the Kingdom of Yugoslavia and the Soviet Union remained frosty. It was not until June 1940 that the Kingdom of Yugoslavia formally recognised the USSR and established diplomatic relations, one of the last European countries to do so. Since 1920, the government of the Kingdom of SHS welcomed tens of thousands of anti-Bolshevik Russian refugees, mainly those who