Among the criminal orders issued before the invasion was for the execution of captured Soviet commissars and disregard for Germany's legal obligations under the 1929 Geneva Convention.

Soviet Jews, political commissars, and some officers, communists, intellectuals, Asians, and female combatants were systematically targeted for execution.

Deaths among these Soviet prisoners of war have been called "one of the greatest crimes in military history",[3] second in number only to those of civilian Jews but far less studied.

[9][10] Due to supply shortages and inadequate transport infrastructure, the German invaders planned to feed their army by looting (although in practice they remained dependent on shipments from Germany)[11][12] and to forestall resistance by terrorizing the local inhabitants with preventative killings.

[30] Anti-Bolshevism, antisemitism, and racism are often cited as the main reasons behind the mass death of prisoners, along with the regime's conflicting demands for security, food, and labor.

[40] Historians like Alexander B. Rossino and Bob Moore also suggested that German disregard for the Geneva Convention and resulting atrocities against POWs developed incrementally from the Polish campaign of 1939, reaching their apogeum in the USSR a few years later.

[74] Although female combatants in the Soviet army defied German gender expectations, the OKH ordered them to be treated as prisoners of war, they could be shot on sight and few survived to reach prisoner-of-war camps in Germany.

[52] Due to the low priority attached to prisoners of war, each camp commandant had autonomy limited only by the military and economic situation.

The use of railcars for transport was often forbidden to prevent the spread of disease,[82] though open cattle wagons were used after October 1941, which resulted in the death of some 20 percent of passengers due to cold weather.

[101] On 21 October 1941, OKH general quartermaster Eduard Wagner issued an order reducing daily rations for non-working prisoners to 1,487 calories—a starvation amount that was rarely delivered.

[106] On 7 August 1941, the OKW issued an order[61] to release prisoners who were ethnically German, Latvian, Lithuanian, Estonian, Caucasian, and Ukrainian.

[118] The selective killing of prisoners held by the army was enabled by its close cooperation with the SS and Soviet informers,[124][125][126] and soldiers often conducted the executions.

[131] German counterintelligence identified many individuals as Jews[132] with medical examinations, denunciation by fellow prisoners, or a stereotypically Jewish appearance.

[126][125] At least 33,000 prisoners were transferred to Nazi concentration camps—Auschwitz, Buchenwald, Dachau, Flossenbürg, Gross-Rosen, Mauthausen, Gusen, Neuengamme, Sachsenhausen, and Hinzert.

[2] In numerous documented instances, captured Soviet soldiers were subjected to torture and mutilation, including being branded with red-hot irons; having body parts such as eyes, ears, hands, fingers, and tongues cut out; having their stomachs ripped open; being torn apart after being tied to tanks; and being burned or buried alive.

[145] Nevertheless, military leaders in the east disregarded his instructions and recruited such collaborators from the outset of the war; Himmler recognized in July 1941 that locally-recruited police would be necessary.

The Trawniki men were recruited from prisoner-of-war camps; largely ethnic Ukrainians and Germans, they included Poles, Georgians, Armenians, Azerbaijanis, Tatars, Latvians, and Lithuanians.

They helped suppress the 1943 Warsaw Ghetto Uprising, worked in the extermination camps that killed millions of Jews in German-occupied Poland, and carried out anti-partisan operations.

As the capture of Red Army soldiers dropped off, Hitler decided at the end of October 1941 to deploy the remaining prisoners in the German war economy.

[180][181] In addition to those sent for labor in late 1941,[182] others were recaptured after escapes or arrested for offenses such as relationships with German women, insubordination, refusal to work,[140][92] and suspected resistance activities or sabotage or were expelled from collaborationist military units.

[189] Hitler halted the transports in mid-August, but changed his mind on 31 October;[190] along with the prisoners of war, a larger number of Soviet civilians were sent.

Many worked for private employers in agriculture and industry, and others were rented to local authorities for such tasks as building roads and canals, quarrying, and cutting peat.

[203] Nazi propaganda portrayed Soviet prisoners of war as murderers,[57] and photographs of cannibalism in prisoner-of-war camps were seen as proof of "Russian subhumanity".

[206] Accurate information about the treatment of Soviet prisoners of war reached Red Army soldiers by various means—such as escapees and other eyewitnesses—and was an effective deterrent against defection[207] although many disbelieved the official propaganda.

[219] In November 1944, the State Defense Committee decided that freed prisoners of war would be returned to the army; those who served in German military units or the police would be handed over to the NKVD.

[221] In an attempt to separate the minority of voluntary collaborators, freed prisoners of war were sent to filtration camps, hospitals, and recuperation centers, where most stayed for one or two months.

[227] After the fall of the Eastern Bloc, the German government set up the Foundation Remembrance, Responsibility and Future to distribute further reparations, from which Soviet prisoners of war were not eligible to make claims.

[60] Historian Viktor Zemskov says that the German figures represent a minimum value,[232] and should be adjusted upwards by 450,000 to account for prisoners who were killed before arriving in a camp.

[238] By this time, more Soviet prisoners of war had died than members of any other group targeted by the Nazis;[239][240][241] only the European Jews would surpass this figure.

[256] Bob Moore likewise noted that "the [Soviet] survivors were [...] victimized and ostracized on their return—their sufferings and mortality forgotten"; tens of thousands judged as collaborators were executed.