How Cold War's most remarkable spy helped Britain save Iran from the Communists - after he asked MI6 to help him beat erectile dysfunction

He was code-named Redwood, one of MI6's most valuable Cold War assets, and his defection to Britain bizarrely hinged on getting treatment for his impotence.The extraordinary story of Soviet double agent Vladimir Kuzichkin has emerged in a new book detailing the chaotic atmosphere of suspicion and treachery which dogged Tehran in the aftermath of Iran's Islamic Revolution.Kuzichkin, a 33-year-old high-flying KGB major, had been despatched to the city as part of a bold plot to overthrow Ayatollah Khomeini using Soviet-backed Iranian communists supported by the Red Army.By late summer 1981 the insurgents had stockpiled weapons and were poised to move on Moscow's word. Tanks were ready to roll across Iran's northern borders from occupied Russian territory in Afghanistan and Turkmenistan.Were it to succeed, the Soviets would take control of the Strait of Hormuz and Persian Gulf oilfields – a nightmare scenario for the West.In the book Redwood: The Untold Story of the Cold War's Most Extraordinary Spy, author Ben Macintyre tells how six months earlier MI6 had posted a new agent, Ian McCredie, to the British embassy in Tehran.In an extract featured in The Times, Macintyre describes this as a bold move by Margaret Thatcher's government given that all foreigners – especially British and American diplomats – had been denounced as spies. Soviet double agent Vladimir Kuzichkin agreed to help MI6 on one condition - that they should help him spice up his love life In the book Redwood: The Untold Story of the Cold War's Most Extraordinary Spy, author Ben Macintyre tells how six months earlier MI6 had posted a new agent, Ian McCredie (pictured), to the British embassy in TehranMcCredie was unaware of the KGB coup plot until, on the morning of October 1st 1981, Kuzichkin emerged from the Soviet embassy and strode across the road, unsolicited, to inform British diplomats he was ready to switch sides.MI6 was initially cautious, fearing entrapment, but eventually gave McCredie permission to go ahead. McCredie picked up his new asset in a quiet, residential street, and hid him under a blanket in the back seat of a Land Rover before driving him to the British embassy.The men headed straight for a bathroom where McCredie, strongly suspecting he had been bugged by the Iranians, turned on taps and switched on the radio before producing a bottle of Stolichnaya vodka.Over a tumbler full, Kuzichkin revealed the coup preparations along with other KGB operations in Iran. He also handed over the Soviet embassy's phone directory containing the names of over 100 spies and diplomats.After agreeing a fallback plan in which Kuzichkin would call with a coded message indicating an emergency, the handsome 6'4' Russian leant forward from the wicker laundry basket on which he was perched.McCredie, who had been sitting on the toilet seat, looked on nervously as a large hand was placed on his knee.'I have something personal to ask you,' said Kuzichkin, 'I have big problem. Will you help me? I have no power in bedroom.'McCredie was mystified. Was this man defecting because the electricity in his apartment was faulty? Kuzichkin explained further: 'You know … in bedroom; I have no power. I cannot make love to my wife. I am sure MI6 has the answer.'Here was Kuzichkin's motive for treachery. He had no interest in financial gain, no one was compelling him to switch sides and while he may have been disillusioned with life in the Soviet state, this alone was not the reason for his visit.Rather, he wanted to save his marriage and saw overcoming erectile dysfunction as key to reviving marital relations with his wife Galina.'In the West, there must be pills, yes?' Kuzichkin asked pleadingly. 'Western medicine is in all ways superior to Russian. A cure.'McCredie patted the massive hand. 'We can help you,' he said, wondering if that was true.MI6 bosses were soon pondering the problem themselves. They turned to the Service's chief medical officer and qualified doctor, Air Marshal Sir Charles Soutar, who suggested some red pills containing iron and vitamins.These were secreted in a ballpoint pen, along with brief medical advice in Russian and smuggled into the Tehran embassy in a diplomatic bag. Viagra it was not but McCredie recalled: 'We hoped they might have some placebo effect.'In the weeks that followed MI6 Russian analysts pored over the Redwood haul – reams of KGB paperwork photographed by Kuzichkin using a British miniature spy camera.But the stress of betraying his country, and his faltering marriage, eventually took its toll. Within six months Kuzichkin had triggered the fallback plan which would see him exfiltrated across the Turkish border.Galina had discovered his activities – perhaps he had told her himself hoping she would flee with him to the West - and he feared she would report him to the KGB.'I have to escape,' he told McCredie. 'You have to get me out of Iran. But hurry. I do not have much time left.'In October 1982 McCredie was given three weeks by MI6 to arrange the defection, which was successful. Almost nothing is known of Kuzichkin's subsequent life in Britain.Extracted from Redwood: The Untold Story of the Cold War's Most Extraordinary Spy by Ben Macintyre (Viking, £25), published on September 10. Order from timesbookshop.co.uk or call 020 3176 2935. Discount for Times+ members.