Islam just isn’t kosher.
Not surprising that hard core Leftists (this one of the racist ultra-nationalist variety) would gravitate to Islam. Totalitarians think alike.
“Judaism and Islam as Opposites,” a 1942 essay by Nazi convert to Islam, Johannes ‘Omar Amin’ von Leers, (d. 1965)
Readers are referred to my previous blog for additional background, on Johannes “Omar Amin” von Leers. There is a reference in Leers’ 1942 essay, translated below, to Muhammad Sabri’s “Islam, Judentum, und Bolschewismus.” This 1938 work by Sabri included the 1937 “fatwa” on the Jews by Leers’ mentor, and eventual Muslim namesake, Hajj Amin el-Husseini, which I have analyzed at length (published here; and as a free pdf here).
Johannes von Leers, “Judentum und Islam als Gegensatze,” Die Judenfrage in Politik, Recht, and Wirtschaft 6, no. 24 (December 24, 1942): 275–78; translated by Steven Rendall. Reproduced from my The Legacy of Islamic Antisemitism, 2008, pp. 619-625.
It is of some interest to read Jewish historians from time to time, not because we can find truth in them, but in order to gain insight into the psychology of Jews. Here we are concerned with one such case that is highly unique—whenever the Jews happen to discuss Muhammad and Islam, they are exceptionally hostile, indeed hateful. For example, Simon Dubnow, in his General History of the Jewish People (Berlin, 3: 282 ff.)  describes Muhammad, but does not fail to note that he was not able to read, and then adds the following:
Thus in the mind of this half-Bedouin there ripened the idea of monotheism, which in him became a fiery passion that drove him to engage in a “holy war” in which any means was permissible. For Muhammad, the knowledge of God was in no way connected with the sublime ethical consciousness that makes the ethical monotheism of the biblical prophets and the one-sided evangelical doctrine of “not of this world” so attractive. The life of Muhammad reveals neither an enchanting personality nor an embodiment of the highest ethical principles capable, even more than the abstract idea, of captivating pious souls. The life of the “Emissary of Allah” and the Qur’an itself are full of examples of how the founder of a religion should not speak and behave. Behind the mask of a prophet we find only too often the eye of a half-savage; the Prophet’s inspiration is overshadowed by the crude passion of the Bedouin who ruthlessly murders in war and does not hesitate to carry off the wives or daughters of the men he murders in order to add them to his harem. All these character traits of Muhammad are particularly clear in his behavior with regard to Jews in Arabia.
This is not historical writing, but rather a campaign of hatred and libel.  First of all, Muhammad was neither a Bedouin nor a half-Bedouin; instead, he was a member of the old family of urban nobility in Mecca, the Quraysh, so the Jewish critic Dubnow obviously has not read the Qur’an, since he makes such an egregious error. But one thing this passage surely betrays—the Jews’ mortal hatred, fourteen hundred years later, for the man who gave birth to the most recent and, in many respects, the most successful of the world religions. The clash between Muhammad and Jewry is not well known, but is actually very interesting. Even before Emperor Titus’s destruction of Jerusalem (70 CE) there were already a few Jews in Arabia, and after the destruction of Jerusalem large groups emigrated to Arabia, settled in Arabian cities, and there carried on active agitation on behalf of Judaism. The three tribes, Banu Qaynuqa, Banu Nadir, and Banu Qurayza, took up residence especially in the city of Yathrib, while other Jews settled in Khaybar, Fadak, Taima, and Wadi-el-Kura—cities that were in fact fully under their control. There were also Jewish groups in southern Arabia, as far south as Aden. The Jews consciously pursued their mission; if many Jewish tribes had the same particularist spirit, the same tribal feuds, and the same customs of blood revenge as the Arabs, this was frequently not because the Jews were becoming Arabized, but on the contrary because in these Jewish tribes there were many converted Arabs. However, the headquarters of the area taken over by the Jews was Yathrib, from which emanated Jewish agitation; there, the three previously mentioned Jewish tribes had intervened in the conflicts between the two largest Arab tribes, the Aws and the Khazraj (sometimes referred to collectively as Banu Qayla),  which they incited against each other and in this way took control over the city. This penetration was achieved by means of economic activity, settlement, and trade, but above all by the Jews’ spiritual influence. To be sure, Christian influences from Byzantium and Abyssinia were also involved, but of the foreign religious creeds Judaism was the most widespread, active, and successful.
The Jews later sought to prove how much Islam had borrowed from Judaism. It is characteristic of Judaism’s vanity that it always sees itself as the origin of all new knowledge. In reality some external respects in which Islam and Judaism agree were borrowed not from Judaism but rather from ancient Oriental folk customs.