Newly unveiled details from the Cold War era reveal the extensive intelligence gathered on the Soviet-backed Iranian communist party, the Tudeh, including plans to overthrow the Ayatollah-led regime and install a pro-Russian government. The intelligence was provided by a Soviet defector known by the codename Redwood, whose revelations detailed weapons caches, underground military networks, and financing channeled to party leaders.

In September 1982, following high-level deliberations, British intelligence, alongside the CIA, passed this information to Iranian secret services during a meeting held in Pakistan. The subsequent crackdown led to the mass arrest and execution of thousands of Iranian communists and their families. The event remains a studied case within MI6’s training programs at Fort Monckton in Gosport, Hampshire, as an example of the moral complexities faced by intelligence agencies during the Cold War.

Within MI6, debates emerged about the ethical implications of sharing the intelligence, with some questioning whether facilitating such a harsh repression was justifiable. However, proponents argued that the priority was to prevent a Soviet expansion into Iran, emphasizing the necessity of using critical intelligence despite the severe consequences. “In the circumstances, what else could we have done? Ignore it? Allow the possibility of a Soviet takeover of Iran?” remarked one former intelligence operative.

The immediate effect of the intelligence operation was to solidify the establishment of the Islamic regime in Iran by eliminating communist opposition. However, Britain and the United States derived little gratitude from the Iranian leadership, and the result has been described as both a Cold War victory and a strategic setback, given the emergence of a new adversarial regime.

The long-term ramifications continue to influence geopolitics. While initially opposing Tehran, Russia now supports Iran by providing drone technology and military backing, reflecting an ongoing strategic contest reminiscent of the Cold War's “Great Game.”

The Soviet defector at the center of the operation was exfiltrated to the United Kingdom, where he adopted a new identity as Alexander Larkin and retrained as an acupuncturist. In a remarkable twist, one of his patients was actor Alec Guinness, who was suffering from chronic back pain during the period he portrayed the fictional spy George Smiley. Despite this discreet post-intelligence career, the defector struggled personally and ultimately succumbed to alcoholism. Intelligence operatives maintained close ties to him, underscoring the agency’s commitment to its assets.

Meanwhile, the author who brought these revelations to light, Ben Macintyre, is engaged in several projects including the upcoming third season of "SAS Rogue Heroes," a series adaptation set in occupied France during World War II. A new six-part adaptation of his previous work on the 1980 Iranian embassy siege is also slated for release in early 2027, featuring a cast led by Omid Djalili and Danny Dyer. Macintyre highlights the nuanced portrayal of the SAS’s role, focusing on the tense psychological battles within the embassy as much as the eventual armed confrontation.

The story of Redwood encapsulates a complex intersection of espionage, geopolitical strategy, and personal struggle, illustrating the profound and often unseen consequences of intelligence work during one of the most volatile periods of modern history.