According to the widespread opinion in historiography, the political initiatives and ideas of the Communist Party of Germany (KPD) were imposed solely by the will of the Soviet leadership and the dogmas of MarxistLeninist theory. The objectives of the participation of the KPD leaders in the Spanish Civil War of 1936-1939 are described as the “Sovietization” of Spain and the search for “Trotskyists” hostile to the USSR. In this connection, the contribution of the German Communists to the antifascist Resistance is seriously underestimated, which is reflected in the researchers’ analyses of the plans for the future arrangement of Germany. When considering projects for the reorganization of postwar Germany in 1944-1945, scholars only consider the scenario of the 1917 Soviet Russia as a model for the reflections of the Communist leaders. However, perusal of archival sources suggests that the involvement of German Communists in the Spanish Civil War had a significant influence on these projects. This gave rise to the forms of Resistance which became even more relevant and advanced during the Second World War (e.g. visits by delegations of writers and politicians to prisonerofwar camps). The war showed that the theoretical concepts of the Communists underwent transformations driven by realities. It was an indication that the ideas of the KPD were similar to those of their nonCommunist contemporaries. Practices established in the Spanish Republic, which the KPD leaders did not recognize as socialist, helped to clarify the concept of a “democratic republic”, as used in the KPD’s addresses to their compatriots. Ideas borrowed by the Communists from their Spanish experience and incorporated into the projects for the future arrangement of Germany made it possible to approach problems from a national perspective. However, the Communists’ involvement in the Spanish Civil War did not bring practical success. Technical problems prevented proper propaganda dissemination from Spain, while the progress of the Fascists was a testimony to the invincibility of Hitler’s troops. Finally, the KPD members themselves, who worked clandestinely in Germany and doubted the correctness of the proposed tactics, contributed to the failure of the leaders.