Doctors’ plot was a culmination of Stalin’s anti-Jewish campaign. It has actually started with the cases of “Jewish antifascist counsil” and “ Zionist conspiracy within (M)KGB”.
Both cases were retaliation on people supporting Israel (primarily within Czech communist party, KGB and Soviet air forces), thus second case was also another Stalin’s paranoid purge in the first place.
It is not heavily advertised fact but Soviets did a lot of work to make Israel happen. An idea was heavily opposed by UK, FDR was against it as well in terms of solidarity with Churchill, but Soviets has pulled it backed by Jewish intellectuals in US.
“Jewish antifascist counsil” were community organizers working for Soviet cause in the West during WWII. Their mission was fundraising, pushing for lend-lease, providing good press for the Soviets etc. In return Soviets promised them to help in establishing a Jewish state in Palestine.
Under pressure from inside US government has finally backed it too.
Both British authorities and Arabs were unimpressed to say the least but Soviets has started pouring captured German weapons via Czechs and provided training like they do in 3rd world now.
The problem is Israel hasn’t come further kibbutz with socialism and started to lean towards the West since the very beginning.
Stalin thought it was a betrayal and went mad. Everyone involved was declared a pro-US conspirator. Jewish counsil was first to get purged, next came the Czech government used as cover for Soviet support of Israel, next came Air Force and KGB training Israel’s airmen, intelligence and special forces.
It was actually a start of blatant Soviet antisemitism, before 1947 you could probably have a death sentence for an antisemitic joke in Moscow.
I also firmly believe it was what finally killed Stalin. It was one thing to purge Soviet military before WWII but absolutely different with “Zionist KGB” and Jewish doctors. These groups certainly had teeth to bite back.
The USSR's pro-Zionist position was created in the late 1940's in part as a way of driving the British out of the Middle East. Soviet propaganda even called for Israeli and Arab armies to join together to defeat "British imperialism." And while the USA recognized Israel first, it was only de facto The USSR gave actual de jure recognition. And yes, the Russians gave the Czech Communists the go-ahead to supply Israel during the arms embargo (though it must be noted that the Zionists had begun negotiations with non-Communist Czechoslovakia, though that country fell to Communism in 2/'48, three months before the War of Independence.
However, for whatever reason, the Soviets turned against Israel after just a few years, this time ordering their Czech underlings to supply the Arabs. Soviet propaganda became anti-Israel and pro-Arab in the early '50's, even though the Israelis themselves at this time took a position of neutrality and refused to take sides in the Cold War. Israeli leaders at the time stated that they were unaware of any anti-Soviet Bloc activity on their part and could not understand Russia's hostility. But Russia had definitely become hostile and took the side of leftist Arabs like Nasser, though apart from a few days in the '50's they didn't break diplomatic relations with Israel until 1967 (and Cuba didn't until 1973).
The Six Day War is often considered the watershed event that caused the Communist bloc to become anti-Israel, but it had already long done that, despite helping Israel to come into existence.