The PKWN used a combination of repressive and co-optive measures . It appealed to patriotic sentiment , sponsored cultural activities , and implemented a popular and long-overdue land reform . No revolutionary changes were introduced beyond the land reform . The new Polish army , largely staffed with Soviet officers ( most of the Polish officer corps present in the east was eliminated in the Katyn massacre or left the Soviet Union with Anders ' Army ) , retained the appearance of a national army and participated in the Soviet offensive all the way to Berlin
Katyn massacre
Katyn massacre
Polish Committee of National Liberation