“Olof Palme is also a Social Democrat. Why is he so different from bloody [Harold] Wilson?” Such was the question the English theater critic Kenneth Tynan posed to a twenty-three-year-old Tariq Ali in a Stockholm restaurant in January 1967. Ali replied that it was Sweden’s military neutrality that gave Palme, then a senior cabinet minister, leeway to host the International War Crimes Tribunal in Stockholm. Organized by philosophers Bertrand Russell and Jean-Paul Sartre, the symbolic tribunal put the United States on trial for its crimes in Vietnam.

Neutrality certainly played some role in Palme’s decision — but it wasn’t the full story. As Palme famously told fellow Swedish Social Democrats in 1964, “Politics, comrades, is to want something.” While Britain’s Labour prime minister Harold Wilson rebuffed Russell’s request to host the tribunal in London, Palme was no ordinary social democrat. He was a deeply committed internationalist who enthusiastically supported various anti-fascist and anti-imperialist struggles from the 1960s until his tragic assassination in 1986.

Prime minister of Sweden from 1969 to 1976 and from 1982 until his death, Palme showed that a skilled politician who truly did “want something” could straddle the worlds of activism and statecraft — supporting international solidarity efforts at home while empowering movements for human dignity abroad. Decades later, the culture of solidarity he brought to the forefront of Swedish politics is embattled, even under attack, from many in his old party. But Palme’s legacy can inform the foreign policy program of left-wing leaders vying for power even today.