Western studies, particularly by Ukrainian diaspora scholars, frequently minimized or ignored the OUN’s and UPA’s involvement in mass murder. They often relied on OUN sources in the West, while ignoring or discounting Soviet sources as unreliable (see, for example, Armstrong).

The American, British, and West German governments provided refuge to many OUN and UPA leaders and members after the end of World War II, and the governments of these countries often withheld or did not properly investigate information about their involvement in the mass killings in Ukraine.

American and British intelligence agencies used many OUN and UPA leaders in exile for intelligence and propaganda purposes against the Soviet Union, and they aided the UPA underground in Soviet Ukraine in the end of the 1940s and the beginning of the 1950s (see Breitman, Goda, Naftali, and Wolf).

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There is also evidence of the involvement of the OUN in international terrorism, in particular, a reported [Reich]-led plot to assassinate U.S. President Roosevelt in 1940–41 and OUN’s assistance to Croatian Ustashi in the assassination of the King of Yugoslavia in France in 1934 (Case 800.20211; Henry Field Papers).

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The analysis of previous studies shows that a very small number of Jews served in the UPA and they primarily had secondary capacities such as doctors. Their presence was motivated mainly by instrumental reasons as they tried to escape [ethnocide], while the UPA used them because it needed medical and other such services that could not be provided by the Ukrainians. A large proportion of these Jews were killed later by the UPA (see Himka, “The Ukrainian;” Spector).

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In addition, 20% of top OUN-B and UPA leaders were arrested and executed, died in detention, or sentenced in the Soviet Union and its East Central European allies, and 10% escaped to the West. None were prosecuted in Western countries, and some, such as Mykola Lebed, who headed the OUN-B in Ukraine in 1941–43, were used by Western intelligence services, in particular the CIA, during the Cold War with the Soviet Union (see Breitman, Goda, Naftali, and Wolfe).