Resistance was more extensive but still largely ineffective for most of the war in Yugoslavia. In that ethnically torn country massacre, reprisal, and active armed resistance was hardly distinguishable from civil war. The only strategically significant resistance in the German rear occurred along the Eastern Front, where large partisan units formed locally or were joined by thousands of former Red Army troops, cut-off by the Germans during earlier campaigns. . The Polish Home Army and Ukrainian nationalist resistance groups also carried out many acts of military sabotage and ambush. The Wehrmacht and Waffen-SS retaliated everywhere in the most savage manner they could imagine, making German rear areas a world unto themselves, places shorn of pity or mercy on either side, with only torture, mutilation, and abundant death.
Soviet subjects in German-occupied territory recruited into the Wehrmacht or Waffen-SS, mostly from among prisoners of war but some directly from the civilian population. Most of the Soviet citizens who served in the German armed forces in some capacity were non-Russian: Cossacks, Tatars, Turkmen, Armenians, Georgians, and men from several Muslim communities from the Caucasus; along with Balts, Belorussians, Poles, and Ukrainians. Perhaps 800,000 served the Germans in some military capacity. Most were formed into battalions and assigned to German divisions, although some division-sized units fought in the Waffen-SS. Some Osttruppen battalions fought partisans in Italy and Yugoslavia. Sixty battalions faced the Western Allies in Normandy. Most were used by the Germans as cannon fodder on the Eastern Front.
Armenians, Azeris, Georgians, Tatars, Turkmen, and others from several small Muslim ethnic groups from the Caucasus who fought in “legions” alongside the Wehrmacht or Waffen-SS.
Auxiliary police drawn from the local, non-German population who worked with German occupation authorities in eastern Europe, especially the Sicherheitspolizei.