[T]he war to the West remained ‘a political struggle’ (MacKenzie, 1995: 97), while to the East it was all‐out war. From the beginning, Hitler had regarded the war to the East not as ‘a formal battle between two states, to be waged in accordance with the rules of International Law, but as a conflict between two philosophies’ (Field Marshall Wilhelm Keitel’s Nuremberg testimony, quoted in MacKenzie, 1994: 505). Accordingly, [Fascist] propaganda described the conflict with the Soviet Union as one between two mutually exclusive worldviews, the Soviet one being branded ‘Jewish Bolshevism’ (Schulte, 1988: 228).
For Hitler (quoted in Streim, 1982: 27), this meant specifically that the army had to distance itself from the traditional point of view that still held fast in the West, according to which enemy soldiers were comrades‐in‐arms united by a shared set of values and a sense of professional solidarity: ‘The communist is before [the war] not a comrade‐in‐arms and after [the war] not a comrade‐in‐arms’. With nothing uniting the actors in this conflict, there was also nothing that called for restraint, as it was not the aim of the war in the East ‘to conserve the enemy’ (Hitler, quoted in Hartmann, 2009: 309, footnote omitted).
Schulte (1988: 150) in this respect writes that ‘documents from the highest level impressed on the [Axis] troops [on the Eastern front] that they were engaged in an ideologically based racial war of extermination […] that was by its very nature qualitatively different from the conventional war […] conducted in the West’. According to Hitler, the point in this war was not to win against the enemy, but to eradicate him once and for all (Streim, 1982: 27).
[The Third Reich] thus approached its relation to its Eastern and Western enemies in two fundamentally different ways: To the East, local populations as separate entities were to disappear through eradication or assimilation, with [the Third Reich] expanding into their territory, while to the West, relations between the enemies as separate entities were expected to outlast the war, hatred being understood merely as a symptom of current hostilities that should not replace mutual respect as the fundamental characteristic of relations.18
(Emphasis added. Source.)