Until the Lubavitcher rebbe, Joseph Isaac Schneersohn, was forced out of the USSR in 1927, his was the largest ḥasidic court to remain in the country. And even after his departure with many of his followers, Chabad-Lubavitch continued to maintain a significant network in the Soviet Union—much of it operating underground to avoid tangling with the authorities—which remained in place until the collapse of Communism. Many Chabad Ḥasidim nonetheless attempted to flee in the years just after World War II, raising the hackles of the political police. Dovid Margolin writes:
On June 6, 1950, Mikhail Popereka, a deputy minister of the Ukrainian branch of the MGB, [or] Soviet secret police—the precursor to the KGB—drafted an eleven-page memo on the status of the ongoing investigation into the case of the “Ḥasidim” and sent it to Viktor Abakumov, the minister of state security of the Soviet Union, [i.e., the head of the MGB]. Marked with a hand-written “Top Secret,” the report synopsized information gathered by the MGB over the course of its investigation into “the Schneersohn anti-Soviet organization” via foreign agents, informants, and interrogations.
An anti-Soviet center headed by the “tsaddik Schneerson”—standard shorthand for . . . Joseph Isaac Schneersohn in Soviet documents—had been set up in New York by American intelligence under the guise of a yeshiva, a European branch established in France, and all of it connected to an extensive anti-Soviet network within the Soviet Union. This, at least, is how the Soviet Union’s intelligence apparatus saw it, all the way to the top.
It was Abakumov who in October of 1946 first alerted Stalin to the threat posed to Communism by “Jewish bourgeois nationalism” and launched into the post-war anti-Semitic campaign against “rootless cosmopolitans,” i.e. the Jews. This dark period would see the liquidation of the Jewish Anti-Fascist Committee—the Jewish organization Stalin had established during the war to rally support to the Soviet cause and raise much-needed funds, whose members were arrested and shot after the war—and the lead-up to the Doctors’ Plot, in which Jewish doctors were announced to have been part of a vast conspiracy to poison Soviet leadership, the development of which was only halted with Stalin’s sudden death in 1953.