Jews clearly never had full control of the USSR despite early over-representation in the central committees.
By the 1930s, Stalin (a Gerogian Gentile) had full control of the government and purged out most Jews except for a few who were loyal to him. He had Trotsky, Zinoviev, Kamenev, Yagoda, and others executed. He also had Rudolf Slansky and other Jewish communists in Czechoslovakia executed in a mass purge and accused them of "Zionist conspiracy" at their trial.
In 39' Stalin signed a deal with Hitler that helped Hitler expand into Poland and start rounding up Jews, a deal that "Judeo-Bolsheviks" like Trotsky opposed. Stalin fired his Jewish foreign minister Litvinov and replaced him with a Russian Gentile, Molotov, specifically to make Hitler happy to get the Molotov-Ribbentrop deal signed.
Stalin was steering that ship, nobody else.
Then the USSR initiated 50 years of hostilities to Israel, backing all its Arab enemies with arms. SO did every other Soviet Bloc state and Mao's Red China, all of whom backed the Arabs against Israel.
Jewish communists were also anti-Zionists who supported that.
