In April 1945, Joseph Stalin ordered the arrest, trial, and imprisonment of all the bishops and thousands of priests, monastics and laity of the Greek Catholic Church of Ukraine (today known in the West as the Ukrainian Catholic Church). The then primate of the church recalled:

Within a year the largest non-Roman, Catholic Church was officially liquidated. A church with ten bishops, 3,470 clergy, 1,090 nuns and over four million faithful became the largest illegal Christian community in the world. For almost forty-five years Greek Catholics were forced to hide their religious convictions, or feign Orthodoxy, or endure arrest, fines, even imprisonment. On 1 December, 1989 that persecution officially ended with the announcement by N. Kolesnick, chair of the Ukrainian Council for Religious Affairs, that Greek Catholic communities would be allowed to register with the authorities.

The change in Soviet policy towards the Greek Catholics is indicative of the depth of transformation in the policies of the USSR. For years the Greek Catholics were not tolerated because of their ties with the Vatican, their nationalism, and their religious beliefs. In the 1980s Soviet attitudes to all of these have changed dramatically, with profound consequences to the resurgent Greek Catholic Church.