Robert Soblen (born Sobolevicius; November 7, 1900 – September 11, 1962) was a prominent member, with his brother, of the OGPU (KGB) which monitored & betrayed Leon Trotsky in Paris especially.

They were very active in French and German Trotskyist movements, handling both Trotsky's secret correspondence to the Soviet Union and publication of his Bulletin of the Opposition.

According to Jack Soble's testimony during Robert's trial, they were personally granted permission for the move by NKVD director Lavrenty Beria, on condition that they assist in Soviet espionage activities in the United States.

According to testimony at his trial, Soblen's activities also included spying on the Trotskyist movement in the United States and transmitting stolen intelligence documents and military information to the Soviet Union.

[5] Soblen's brother Jack was arrested in 1957 and charged with espionage, primarily based on the testimony of Hollywood producer Boris Morros.

Soble pleaded guilty to the espionage charges, made a detailed statement of his activities, and was sentenced to seven years in prison.

He was charged with providing the Soviet Union with secret OSS documents in World War II and photographs of a U.S. nuclear testing site in 1950.

He was arrested in his hotel room shortly after his arrival, and the Israeli government declared that the Law of Return was not an open invitation for Jewish criminals to immigrate to Israel.

The vote failed, but the controversy may have contributed to the passing of Israel's "Offenses Committed Abroad Act" in 1978, which sharply restricted the circumstances under which Israeli citizens could be extradited.