He was only 19 when he foiled an attempt by Nazi Germany to assassinate the Big Three allied leaders.

The legendary Soviet spy, Gevork Vartanyan, who foiled Nazi Germany's plot to assassinate Joseph Stalin, Franklin D. Roosevelt and Winston Churchill in Tehran in 1943, died in a Moscow hospital on Tuesday at the age of 87.

In a message of condolences to Mr. Vartanyan's surviving wife and fellow spy, Goar, Russian President Dmitry Medvedev praised the super spy's role in “brilliant special operations which became part of history of the nation's foreign intelligence.”

Tehran-43 was one of Mr. Vartanyan's many glorious feats. He was only 19 at the time, but already had more than three years of work as an undercover agent in Tehran, where he lived with his father, a Soviet intelligence officer of Armenian-Iranian descent. In 1942 he infiltrated a British spy school that sent it graduates to the Soviet Union (“The British intelligence is smart but very mean,” recalled Mr. Vartanyan.).

On the eve of the allied powers conference in Tehran in November 1943, the Soviet intelligence learned about a Nazi plan to kill the Big Three Allied Leaders from a drunken Waffen-SS officer who boasted about the plot to a Russian master spy in occupied Ukraine.

Adolf Hitler had ordered operation “Long Jump” after the Nazi intelligence broke U.S. secret codes and learned the leaders would gather in Tehran to discuss the opening of a second front in Western Europe to help Soviet forces defeat the Nazi armies.

Northern Iran was occupied by Soviet troops at the time, but Tehran was swarming with Nazi agents who easily camouflaged themselves among some 20,000 German refugees living in the Iranian capital.

Mr. Vartanyan's seven-member group tracked down an advance team of six Nazi agents air dropped near the city of Qum and intercepted their radiograms. After it was learned that a second group of Nazi commandos headed by the famous spy and saboteur Otto Scorzeny was to arrive in Tehran, the advance group was arrested and made to play a radio game against the Nazi intelligence.

“It was tempting to capture Scorzeny himself, but we could not take any risks as the Big Three were already in Tehran,” Mr. Vartanyan said in an interview four years ago. “We let a Nazi radio agent alert his handlers of the arrests and Berlin called off the operation.”

It was only several years ago that the Russian government revealed Mr. Vartanyan's role in the Tehran operation, but his lengthy track record remains classified. Mr. Vartanyan once said he spoke eight foreign languages and in five of them was “as fluent as in my native tongue,” but he would not name any of the languages because this would disclose “the geography of my undercover operations.” The only thing he would say about his and his wife's work after Tehran-43 is that “it pales in comparison with many of our successes elsewhere.” Mr. Vartanyan was awarded the Gold Star Medal of the Hero of the Soviet Union, the highest Soviet award, for his 67-year-long service. After retiring in 1992, he helped train young intelligence agents. Mr. Vartanyan's wife has also been honoured with state awards.

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