Ohlendorf joined the
SD in 1936 and became an economic consultant of the organisation. Like other academics such as
Helmut Knochen and
Franz Six, Ohlendorf had been recruited by SD talent-scouts. Attached to the SS with the rank of SS-
Hauptsturmführer, by 1939 he had reached the rank of SS-
Standartenführer and was appointed as head of Amt III (SD-Inland) of the
Reich Security Main Office (RSHA), a position he kept until 1945. His role in collecting intelligence from his secret-police agents was disliked by some of the Nazi leadership.
Reichsführer-SS Heinrich Himmler once characterized Ohlendorf as "an unbearable Prussian" who was "without humour". Nonetheless, Ohlendorf was instrumental as a member of the SD in shaping Nazi economic doctrine, which became "increasingly virulent as the war progressed" as he attempted to mould the economy "in an ethnic context". It was Ohlendorf's responsibility as head of the SD-Inland to collect data and scientifically to examine social, cultural, and economic issues, assembling reports to his superiors in the Nazi government. Routine public-opinion surveys—which were under the purview of Ohlendorf and of SS-Major
Reinhard Höhn—constituted some of these reports. These public-opinion polls on the social climate of Nazi Germany were both unpopular and controversial. In June 1941,
Reinhard Heydrich appointed Ohlendorf as commander of
Einsatzgruppe D, which operated in southern
Ukraine and
Crimea. Joining the
Einsatzgruppen was an unappealing prospect and Ohlendorf refused twice before his eventual appointment. Transfers from the RSHA to the
Einsatzgruppen were in part due to personnel shortages but also to keep the initial killing-operations confined to those who already knew the details, such as Ohlendorf,
Arthur Nebe, and
Paul Blobel.
Einsatzgruppe D was the smallest of the task forces, but was supplemented by Romanians along their way through the killing fields of
Bessarabia, southern Ukraine, and the Caucasus. Additional manpower for
Einsatzgruppe D came from Ukrainian auxiliary-police formations. Supporting military operations, Ohlendorf's group was attached to the
Eleventh Army. Ohlendorf's
Einsatzgruppe in particular was responsible for the 13 December 1941 massacre at
Simferopol, where at least 14,300 people, mostly Jews, were killed. Over 90,000 murders throughout Ukraine and the Caucasus are attributed to Ohlendorf's unit. Ohlendorf disliked the use of the oft-employed (shot to the back of the neck) and preferred to line up victims and fire at them from a greater distance; this method allegedly alleviated personal responsibility for the individual murderers. All forms of contact between the firing squads and victims were limited—per Ohlendorf's insistence—until the last moments before the killing started, and up to three rifleman were allocated to each person about to be shot. To ensure the group-killing mentality, Ohlendorf forbade any commando from taking individual actions and explicitly instructed his men not to take any of the victims' valuables. One of Ohlendorf's most trusted "proper" military-style murderers,
Haupsturmführer , once exclaimed, "A man is the lord over life and death when he gets an order to shoot three hundred children—and he kills at least one hundred fifty himself." Many of the killing operations were personally overseen by Ohlendorf, who wanted to ensure they were "military in character and humane under the circumstances". The number of persons killed under the leadership of
Einsatzgruppen commanders such as Ohlendorf are "staggering", despite the use of varying murder techniques. On 1 August 1941,
Einsatzgruppen commanders, including Ohlendorf, received instructions from
Gestapo chief
Heinrich Müller to keep headquarters (
Hitler especially) informed of their progress in the East; Müller also encouraged the speedy delivery of photographs showing the results of these operations. During September 1941, Ohlendorf's group slaughtered 22,467 Jews and communists at
Nikolayev near the Black Sea port of
Odessa. Due to the 's insistence that Ukraine's agricultural production was needed to sustain its military campaign, Ohlendorf was asked by the army during October 1941 to refrain from killing some of the Jewish farmers—a request he honored—but one which earned him Himmler's contempt. Nonetheless, just a month prior in September 1941, Ohlendorf announced to his men that "from now on the Jewish question is going to be solved and that means liquidation". From that month forward, the
Einsatzgruppen had begun the process of systematically shooting not just men but women and children, a transition that historian
Peter Longerich terms "the decisive step on the way towards a policy of racial annihilation". Between February and March 1942, Himmler ordered that
gas vans should be used to murder women and children so as to reduce the strain on the men, but Ohlendorf reported that many of the
Einsatzkommandos refused to utilize the vans since burying the victims proved an "ordeal" afterwards. Gas-van killing operations were usually conducted at night to keep the population from witnessing the macabre affair. After the victims' deaths, Jewish were forced to unload the bodies, clean the excrement from inside the van's gas chamber, and once the clean-up was complete, were themselves immediately shot. As far as Ohlendorf was concerned, the gas vans were impracticable for the scale of killing demanded by Himmler; namely, since they could only kill between fifteen and twenty-five persons at a time. Historian
Donald Bloxham characterises Ohlendorf as a bureaucrat who was trying to "prove himself in the field". Another historian,
Mark Mazower, describes Ohlendorf as a "gloomy, driven, self-righteous Prussian". His commitment to the Nazi cause kept him in Ukraine longer than any of his comrades, and while he may have disliked the political direction in which Germany was headed, he never registered complaints about murdering Jews. He did, however, express misgivings about the barbarity and sadism being meted out by the Romanian units that accompanied the
Einsatzgruppen in their murderous tasks, since they were not only leaving a trail of corpses in their wake, they were also pillaging and raping in the process. He also complained about the Romanians driving thousands of frail elderly persons and children from Bessarabia and
Bukovina—all incapable of work—into German-held regions, whom Ohlendorf's men forced back into Romanian territory, but not without killing a significant percentage of them as a result. Ohlendorf devoted only four years (1939–1943) of full-time activity to the RSHA, for in 1943, in addition to his other jobs, he became a deputy director-general () in the
Reich Ministry of Economic Affairs (). Sometime in November 1944, he was promoted to SS–
Gruppenführer. Believing their expertise invaluable, Ohlendorf,
Ludwig Erhard, and other experts concerned themselves with how to stabilize German currency after the prospective end of the war. Hoping to salvage the reputation of the SD, Ohlendorf offered his services in the hopes that he could shape the postwar reconstruction of Germany, but along "National Socialist lines", remaining convinced—as was Admiral
Karl Dönitz (who would make Ohlendorf his
de facto economics minister under
Albert Speer in the
Flensburg Government of May 1945)—that some form of Nazism would ultimately survive. In May 1945, Ohlendorf participated in Himmler's flight from
Flensburg. He surrendered to British authorities on 23 May 1945. For several weeks after his arrest, he was carefully interrogated, during which he revealed the criminal nature of the German campaign in the East. ==Nuremberg trials==