Forty Years Later, Nobody Has Been Convicted of Killing Sweden's Prime Minister. A New Theory Suggests They Know Why.

STOCKHOLM — On the evening of February 28, 1986, Swedish Prime Minister Olof Palme and his wife Lisbet decided to go to the cinema. He sent his bodyguards home. They took the subway. They watched a film. On the walk back, at the corner of Sveavägen and Tunnelgatan, someone shot Palme twice in the back at close range with a .357 Magnum revolver. He was pronounced dead at the scene. The shooter disappeared into the night.

No one has ever been convicted.

The case has been open, technically or practically, for four decades. It has consumed more investigative resources than any other criminal investigation in Swedish history. It has destroyed careers, produced multiple competing theories, implicated intelligence services on three continents, and generated a volume of books, documentaries, and academic papers substantial enough to constitute its own library. The official conclusion, issued in June 2020, named a man called Stig Engström — known as 'the Skandia Man' for the insurance company he worked near — as the most likely perpetrator. Engström had died in 2000. He could not be tried, questioned, or confronted with the evidence. The case was closed.

The conclusion was widely criticized. Former prosecutors, retired police investigators, and multiple journalists published detailed objections to the evidence, calling it circumstantial, selectively assembled, and insufficient to support the charge. The Swedish public, which had never fully accepted the lone-gunman theory to begin with, remained largely unconvinced.

Now, a new investigation published this week by Haaretz, and supported by parallel reporting from CovertAction Magazine and independent researchers, has revived the theory that Palme was killed not by a disturbed loner but by an organized network — one with Cold War origins, NATO adjacency, and a specific political motive.

The network in question is known, in intelligence circles, as 'Stay Behind.' It was a real program. It was not a conspiracy theory.

Stay Behind was a NATO-coordinated operation established across Western Europe after World War II. Its purpose was to create hidden resistance cells — armed, trained, and pre-positioned — that would activate in the event of a Soviet invasion. In neutral countries like Sweden, which was not formally in NATO, parallel structures were created anyway, with the knowledge of a small number of senior officials and the operational support of American and British intelligence. The cells were designed to conduct sabotage, propaganda, and, in some documented cases, targeted assassination. They were meant to be undetectable. Most of them were.

Olof Palme was, by any reasonable assessment, an enemy of everything the Stay Behind network stood for. He had condemned the United States' war in Vietnam in terms that prompted the American ambassador to Sweden to be recalled. He had criticized South Africa's apartheid government at a time when Western intelligence services were cooperating with Pretoria. He had sold arms to Cuba. He had been publicly supportive of the African National Congress. He had advocated for a nuclear-free zone in Europe and sought to normalize Sweden's relationship with the Soviet Union — a position that alarmed hardliners in NATO-aligned intelligence circles who viewed any such outreach as potential accommodation of the enemy.

A former CIA officer, in interviews conducted before his death, reportedly described Palme as 'the most dangerous socialist in Western Europe' — not because he was a communist, but because he was credible, popular, and genuinely committed to neutrality in a way that threatened the logic of Cold War bloc alignment.

The Stay Behind theory holds that senior figures within Swedish military intelligence, coordinating with NATO-affiliated contacts, authorized or facilitated Palme's killing. The motive: to remove a leader whose foreign policy was seen as a strategic liability and, secondarily, to trigger a political shift in Sweden toward the right. Swedish researchers affiliated with CovertAction Magazine published a detailed analysis in February 2026 arguing that the assassination did exactly that — Sweden's political landscape shifted measurably rightward in the years following Palme's death, 'just as his assassins appear to have planned.'

Swedish authorities have never formally investigated the Stay Behind angle. The existence of a Swedish Stay Behind network was not officially acknowledged until 1997, more than a decade after the murder. Documents relating to Swedish military intelligence operations in the relevant period remain classified.

A spokesperson for the Swedish Security Service, contacted for comment, said the agency does not comment on ongoing or closed investigations. They were asked whether the investigation was ongoing or closed. They said it was closed. They were asked whether new evidence could reopen it. They said they had no comment on that.

Engström, the man officially named, remains dead.