[2][3] He was primarily responsible, together with his wife Goar Vartanian, for thwarting Operation Long Jump, concocted by Adolf Hitler, headed by Ernst Kaltenbrunner, and led by Otto Skorzeny, which was an alleged attempt to assassinate Stalin, Churchill, and Roosevelt at the Tehran conference in 1943.

In 1942 the Nazis intercepted intelligence about a planned meeting in Tehran and devised a sceme to capture or assassinate Stalin, Churchill, and Roosevelt.

After careful planning and deliberation under the personal supervision of Security Police Chief Ernst Kaltenbrunner, Hitler sent his special commando agent, Otto Skorzeny, along with six other men to rendezvous at Tehran and spearhead the operation.

The first tip-off about the planned attempt came from Soviet intelligence agent Nikolai Kuznetsov, under the alias of Wehrmacht Oberleutnant Paul Siebert, from Nazi-occupied Ukraine.

He then spent three decades doing espionage activities in Japan, China, India, France, Italy, United States and West Germany.

In 2003, relying on declassified documents, Yuri Lvovich Kuznets published a book called Tehran-43 or Operation Long Jump, which detailed Vartanian's role at the Tehran Conference.

[2][6][7] Russian Prime Minister Vladimir Putin attended the funeral and paid his respects to Vartanian's widow Goar,[8] a fellow intelligence officer, who died on 25 November 2019.