I guess I'm asking if the KPD played any part in the Soviet counteroffensive on German soil. Alternatively, would KPD membership protect civilians from the violence of the Soviet advance?
Although the postwar SED maintained that KPD activism and antifascist resistance was a heroic page in its history, the actual activities of the KPD during the wartime were rather meager. Internal squabbling in the aftermath of the Nazi seizure of power, indifferent direction from Moscow, and a very proactive policing on the part of the SS had all but destroyed much of the KPD's network within the wider German population. With the notable exception of the Berliner Rote Kapelle (Red Orchestra Berlin) which provided intelligence to the Allies, the KPD's wartime were far from noteworthy.
KPD resistance activities generally fell along two axes: internal organization inside Germany's prisons and KPD exiles working with the Red Army. In the latter case, a number of KPD exiles were crucial in the formation of the Nationalkomitee Freies Deutschland (National Committee for a Free Germany/NKFD) which sought to reach out to German POWs and inculcate antifascist sentiments among these prisoners. The NKFD grew out of the efforts of various KPD exiles like Fred Oelßner or Anton Ackermann that produced German-language propaganda at the start of Barbarossa. But the NKFD's activities were not just limited to propaganda. One of the long-range goals of the NKFD was to create a cadre of pro-Soviet Germans that could assume positions of responsibility in Germany once Hitlerism had been crushed. POWs who joined the organization often received better rations and treatment and a number of NKFD men did end up in positions within the charter generation of the SED. The NKFD often downplayed some of its Marxist tenets, much to the chagrin of a number of exiles, to appeal to the broadest possible base of German soldiers. Nationalist rhetoric was one of the staples of NKFD propaganda, which was at odds with some of the KPD members' experiences in Weimar and the Kaiserreich. Aside from propaganda broadcasts and intelligence work, some trusted NKFD men served in the front to aid in reconnaissance and disruption of the German lines. But the NKFD's main contribution to the war effort was not so much martial, but administrative. NKFD men followed in the wake of the Red Army and served as a liaison to the Soviet military government and the German areas conquered by the Red Army.
Most KPD activism within Germany itself was limited to the prison system where a good many KPD members had been incarcerated. The imprisonment of KPD members had predated the war, but wartime measures led to a further expansion of the sweeps and denunciations, so that many of the major prisons and camps had a strong KPD presence. While the prison officials kept very close watches on KPD leaders like Ernst Thälmann, there were too many imprisoned KPD members to isolate in solitary confinement. This meant that a good many low- and mid-level KPD prisoners managed to scrape together something of a cell organization within the prison system. One of the more dubious results of this organization was that number of KPD men became Kapos (prisoner bloc wardens). Although the SS and prison administrators preferred to delegate to "Greens" (professional, apolitical criminals) for administrating the prisons, the various "Reds" (inmates for left-wing offenses including the SPD) managed to colonize a sizable portion of the German prison system. KPD Kapos though did not lead a flagrant and open resistance; work details might not be done efficiently, but they were accomplished. Instead, the KPD Kapos used their own positions to protect their own members and possibly recruit new ones within the system. There was some husbanding of resources such as weapons and extra food for a prison uprising when the conditions were right. But despite the prominence of uprisings such as the Buchenwald revolt in April 1945 in GDR state mythology, rising up and throwing down the system was not the main goal of the KPD in prison. Survival was of a postwar nucleus of KPD leaders was the main goal.
As the above suggests, KPD resistance did not achieve very much despite the postwar puffery of the GDR. The Allies themselves were aware of this, including the Soviets. A good portion of the adulteration of the NKFD's ideological message came at the behest of the Red Army and Stalin, neither of which held out much hope for a class-based revolution in Germany until after the war. The NKFD itself could not garner much support from German POWs, further justifying Stalin's skepticism. And while there was some small-scale KPD resistance outside of the prisons, the KPD's activities paled in significance when contrasted to the work of other communist parties in occupied Europe such as the French, Italian, and Yugoslavian. The latter groups had actually managed to transition from clandestine broadsheets and occasional sabotage to partisan warfare. Not even the SED could pretend that its wartime activities rose to that level of resistance.
One of the long-term legacies of the KPD's (in)actions in Germany during the war was that it promoted a highly insular and distrustful attitude within the SED to other Germans. It is telling that a majority of the SED's postwar leadership either were involved in the NKFD (Ulbricht, Pieck, Bechler, usw.) or were veterans of the Third Reich's jails (Honecker, Grotewohl, Sindermann, usw.). As First Secretary of the GDR, Ulbricht often heaped scorn in private and public on "native" communists who had remained in Germany and not been jailed by the Third Reich. There was a wide-spread attitude among the NKFD members that such natives' claims to be antifascist were opportunistic, just like their support for fascism was done for allegedly personal gain and power. This meant that a good many NKFD, and later SED, leaders in the Soviet zone were indifferent to pleas from mid- and lower-level party members about the abuses of Red Army troops. In a May 1945 KPD meeting in which the issue of abortions came up in light of Red Army rapes, a number of party delegates demanded that Ulbricht push for facilitating abortions and making a stronger stand. Ulbricht barked back at his raucous subordinates:
People who get so worked up about such things today would have done much better to get worked up when Hitler began the war.
Such sentiments were common among the leadership when presented evidence of Soviet misdeeds in the wake of victory. Only on the lower level did KPD activists and members really appeal to the Soviet military government to rein the excesses of its troops. KPD/SED political meetings and rallies often emphasized that electoral support for the KPD/SED would lead to a return to normalcy and show the Soviets that Germany was not a defeated foe, but a converted ally. Contrary to the public stance in SED newspapers, such meeting also held out the possibility that the Oder-Neisse line was not permanent and that an equitable re-rearrangement of territory was possible between socialist brothers.
But such interventions by the KPD/SED had limited impact on the Soviet military government and the SED/KPD leadership. In the former case, while the Soviet leadership in Germany was increasingly concerned about chronic indiscipline and crimes committed its troops (and this was why it cut the Gordian knot and confined the occupation troops to their barracks in 1947), German pleas to stop requisitions of industrial and economic infrastructure fell on somewhat deaf ears. Moreover, the Soviet military government also had to rein in excessive anti-fascism of KPD local officials who took their denazification duties too far and enriched themselves off of expropriated goods from the accused.
The paltry record of the wartime KPD was reflected in the GDR's commemorative culture of the war. Although it often embellished actual resistance, the dominant tone of SED's public memory of the war was martyrdom. At the base of the Sachsenhausen monument is a statue of two inmates with a friendly Soviet soldier, but the statues are overshadowed by the obelisk containing the red triangles of those KPD men who died there. Buchenwald's memorial features a typical Eastern-bloc heroic statue of square jawed-emaciated men leading an uprising, but this is a small component of the whole monument's layout in which visitors travel first through the mass graves to reach such a triumph. Sachsenhausen likewise features a pieta of emaciated prisoners before its memorial wall. The NKFD featured only a small role in GDR commemorative culture, such as this stamp. The dominance of martyrdom over action in this commemoration only serves to highlight the relative inaction of the KPD during the fascist period. There was little actual resistance for the postwar SED to celebrate.
Sources
Epstein, Catherine. The Last Revolutionaries German Communists and Their Century. Cambridge, MA: Harvard University Press, 2003.
Morina, Christina. Legacies of Stalingrad Remembering the Eastern Front in Germany Since 1945. Cambridge: Cambridge University Press, 2014.
Slaveski, Filip. The Soviet Occupation of Germany: Hunger, Mass Violence and the Struggle for Peace, 1945–1947. Cambridge: Cambridge University Press, 2013.
Weitz, Eric D. Creating German Communism, 1890-1990: From Popular Protests to Socialist State. Princeton: Princeton University Press, 1997.