Hoover advised Sir William Stephenson, head of British Security Coordination for the Western hemisphere, of Bentley's defection, and Stephenson duly notified London. But Kim Philby was the head of the British Secret Intelligence Service's (SIS or "MI6") new Section IX (counter-espionage against the Soviet Union). He was a Soviet double agent who would escape to the Soviet Union in 1963. Philby promptly alerted Moscow about Bentley, and they shut down all contact with Bentley's network, just as the FBI was beginning surveillance of them. Bentley's NKGB contact Gorsky again recommended to Moscow that the American be "liquidated", and again Moscow rejected the idea.