Russia became increasingly antisemitic after 1948.
Assassinations of leading Jewish writers, show trials and large scale antisemitic plans followed, including the so called Prague “Slansky trial”, the planned Russian “Doctors trial” and the planned so called “Zionist trial” and “Wallenberg trial” in Hungary. (The creative sinister script’s theme was that Hungary’s Jewish leaders and two loyal aids of Raoul Wallenberg murdered him in Budapest in 1945….) The accused were arrested and severely to tortured to “coach” them how to perform the scripts in what may have become their last act…
Hitler’s one time allya and co-rapist of Poland, Stalin, had bigger plans for Russian Jews and maybe Jews in the Soviet colonies: large scale deportations or worse.
Jews in the USSR lived in fear.
Stalin collapsed (possibly assisted by secret police chief Beria) shortly before his plans could be put into effect.