Ukrainian Military Organization
The Ukrainian Military Organization (Ukrainian: Українська Військова Організація, UVO) was a Ukrainian resistance and sabotage movement active in Poland's Eastern Lesser Poland during the years between the world wars. Initially headed by Yevhen Konovalets, it promoted the idea of armed struggle for the independence of Ukraine.
Created by former members of the Sich Riflemen in August 1920 in Prague, the UVO was a secret military and political movement. Initially operating in all countries with Ukrainian minorities (that is Poland, Czechoslovakia, Bolshevik Russia and Romania), with time it concentrated on actions in Poland only. It was also active among the Ukrainian diaspora abroad, most notably in Germany, Lithuania, Austria and the Free City of Danzig.
Apart from military education of the Ukrainian youth, the UVO tried to prevent cooperation between Ukrainians and Polish authorities. The UVO was involved in a bitter struggle with the Poles during the 1920s. The group was treated harshly and retaliated with violence. It was, however, rather a military protective group rather than a terrorist underground. It organized a number of assassination attempts on some of the most renowned Polish and Ukrainian politicians, some of which were successful. Among such attempts were a failed assault on Józef Piłsudski and Voivod of Lwów Kazimierz Grabowski on September 25, 1921, the successful murder of Ukrainian poet Sydir Tverdohlib and assassinations of Ukrainian activists Wasyl Pihulak and Iwan Bachmaszczuk in 1922, as well as a failed attack on Poland's president Stanisław Wojciechowski in 1924 and the Nonpartisan Bloc for Cooperation with the Government (BBWR) deputy chairman Tadeusz Hołówko. It organized three bomb attacks on the Eastern Trade Fair in Lwów in 1929, bombings of train stations, railway tracks, pumping stations, burnt and blown up police buildings (e.g. in Yavoriv, Gródek, Uhnów, Lubaczów) and Polish households; it was also active in destruction of telegraph, telephone poles and committed a number of expropriation attacks - amongst them - the robbery of 100,000 złoty (then the equivalent of 20,000 dollars) from a Lviv Post Office in 1925. The terrorist actions of the UVO became one of the reasons for creation of the Polish Border Defence Corps.
In May 1923, Yevhen Konovalets and Friedrich Gempp - the chief of the Reichswehrministerium Abwehr-Abteilung signed an agreement according to which the UVO would conduct espionage work against Poland (providing Berlin with political, military and economic information), while the German side was to provide financial aid and military equipment for "revolutionary activity". By 1927, the Ukrainian Military Organization acquired 9,000 Reichmark from the German intelligence service. The Germans supported military training of Ukrainian Nationalists in Eastern Prussia, whereas the Free City Danzig (Gdańsk) became an important transit place for money, arms and ammunition.
Originally under the nominal authority of the exiled government of the Western Ukrainian People's Republic, in 1925 following a power struggle all the supporters of the Western Ukrainian People's Republic's exiled president Yevhen Petrushevych were expelled.
Although formally UVO existed until World War II, between 1929 and 1934 it became part of the newly formed Organization of Ukrainian Nationalists. Apart from Yevhen Konovalets, notable leaders of the UVO included Andrii Melnyk and Y. Indyshevskyi.
- John Armstrong. Ukrainian Nationalism. second edition Libraries Unlimited, 1963. p 21
- G. Motyka, Ukraińska partyzantka, 1942-1960, PAN, 2006, p. 37
- G. Motyka, Ukraińska partyzantka, 1942-1960, PAN, 2006, p. 43
- G. Lagzi, The Ukrainian Radical National Movement in Inter-War Poland. The Case of Organization of Ukrainian Nationalists (OUN), REGIO, A rewiev of Studies on Minorities, Politics, and Society, 2004, p. 198, 
- Christopher Gilley (2006). A Simple Question of ‘Pragmatism’? Sovietophilism in the West Ukrainian Emigration in the 1920s Working Paper: Koszalin Institute of Comparative European Studies pp.6-13