In his instructions to General Alfred Jodl, Chief of the Army Leadership Staff, Adolf Hitler explains that he regards the war against Russia to be an ideological war, not simply a military conflict.
"This coming campaign is more than a struggle of arms; it will also lead to the confrontation of two world views. In order to end this war it will not suffice merely to defeat the enemy army.. The Jewish-Bolshevik intelligentsia, the hitherto oppressor of the people must be eliminated [beseitigt]."
Hitler here is giving voice to the idea that "Jew" and "Bolshevik" are essentially one and the same category. The Nazi war on communism, socialism, and Bolshevism is thus from their perspective the same as their war on Jews.
This helps explain why they will be willing to devote so many resources to the extermination of Jews even as they are losing to the Soviet forces on the Eastern Front: Jews and at home and Bolsheviks abroad are on the same side, with the former serving as a fifth column that undermines the ability of Germany to fight abroad. Oppressing and killing Jews may thus be perceived as helping rather than harming the front-line military efforts.