'Weitsprung' was a German plan to assassinate Premier Iosif Stalin, Prime Minister Winston Churchill and President Franklin D. Roosevelt at the 'Eureka' inter-Allied conference in Teheran during November and December 1943 (autumn 1943).
German intelligence had learned of the conference’s schedule and location after breaking a US Navy code, and the plot was approved by Adolf Hitler to be undertaken under the supervision by SS-Obergruppenführer und General der Polizei Ernst Kaltenbrunner, chief of the Reichssicherheitshauptamt (Reich Main Security Office), who selected SS-Obersturmbannführer Otto Skorzeny to head the mission. Also involved was the German agent Elyesa Bazna (better known under the codename 'Cicero'), who transmitted key data from Ankara, Turkey.
Soviet intelligence quickly uncovered the plot. The first report about the German undertaking came from the Soviet agent Nikolai Kuznetsov. Posing as German army Oberleutnant, Paul Siebert from Nazi-occupied Ukraine, Kuznetsov got SS-Sturmbannführer Hans Ulrich von Ortel, an officer of the RHSA, to drink too much and then tell him about the operation.
A young Soviet agent, Gevork Vartanian, had recruited a small number of agents in Iran, where his father, also a spy, was posing as a wealthy merchant. It was Vartanian’s group which located an advance party of six German radio operators who had dropped by parachute near Qum, 37 miles (60 km) from Teheran, and followed the men to the Iranian capital, where the German intelligence network provided a villa for them. The Soviet group established that the Germans were in contact with Berlin via radio and recorded communications which were decoded and revealed that the Germans planned to drop a second group of operatives led by Skorzeny for the assassination attempt. Skorzeny had already made a reconnaissance in Teheran, where he had been followed by Vartanian’s group. All the German transmissions were then intercepted by Soviet and British intelligence. However, one of the Germans radioed a message with a secret code indicating that they were under surveillance, and the operation was called off.
Skorzeny himself considered the intelligence coming from Teheran to be inadequate, and did not believe the complex scheme could have worked. When Stalin informed Churchill and Roosevelt about the plan, some members of the British and US delegations doubted the existence of such a plot as the only evidence of its existence was provided by Soviet intelligence. In the UK the Joint Intelligence Committee of the War Cabinet later concluded that the so-called plot was 'complete baloney'. Western studies have continued to doubt the Soviet story. Firstly, the German espionage network in Iran had been destroyed in mid-1943, well before Teheran was chosen as a meeting place. Secondly, more than 3,000 NKVD security troops guarded the city for the duration of the conference without incident. Thirdly, both Roosevelt and Churchill travelled on foot or open Jeep throughout their four-day stay in Tehran. Skorzeny denied the story after the war. In his memoirs, he recalled a meeting with Hitler and SS-Brigadeführer Walter Schellenberg, from the foreign intelligence branch of the Sicherheitsdienst, when they did discuss the feasibility of assassinating Churchill. But Skorzeny said he told Hitler that the concept was unworkable, and that Hitler then agreed with his assessment.