Willem Sassen

Willem Sassen is a Dutch former SS volunteer, wartime collaborator, and journalist who becomes a prominent intermediary among Nazi fugitives in Buenos Aires. His ability to cultivate influential contacts gives him access to men who otherwise conceal their identities, including Josef Mengele, and makes his home the setting for recordings of Adolf Eichmann. After Eichmann’s capture, Sassen sells those recordings and leaves Argentina, a reversal that turns his usefulness as a confidant into a source of suspicion.

From wartime collaborator to Buenos Aires journalist

Sassen’s past resembles that of many of the men he later meets. He volunteered for the SS and served in a Dutch squadron on the Russian front, which advanced into Soviet territory and the Caucasus; he was badly injured. During the Third Reich he worked as a propagandist on Belgian radio and was a high-level collaborator. Arrested after the war, he received a prison sentence in the Netherlands, escaped twice, and eventually reached Ireland. From there he sailed to Argentina in a schooner.

In Buenos Aires, Sassen establishes himself quickly. Although Dutch, he learns Spanish to a high standard within a few months and carves out a place in the country’s social and political circles. He writes for Der Weg, a Nazi-oriented journal that functions as a meeting point for former Nazis and collaborators. His polished articles attract notice: Eberhard Fritsch regards him as the publication’s leading wordsmith and a major contributor to its growing success. Sassen’s authority rests not only on his writing but also on his bearing, fluency, and extensive address book.

A network built on access and trust

At the journal, Sassen moves among figures with histories of wartime violence and postwar flight, including Josef Schwammberger and Reinhard Kopps. The narrative emphasizes that he and Mengele recognize a shared preference for influential company over ordinary social circles. Their first response to each other is guarded, but Sassen’s manner and cultural knowledge make an impression. He drinks whisky and smokes heavily, while Mengele does not smoke; despite that contrast, the two become friends.

Sassen’s wartime record provides a basis for their mutual recognition: both had volunteered for the SS, and both had been arrested after the war. Sassen had escaped imprisonment and made his way to Argentina, while Mengele had arrived under an assumed identity. Impressed by Sassen’s discretion, Mengele confides his real identity and history to him. The trust is consequential: Sassen becomes one of the first people in Buenos Aires to whom Mengele reveals who he is and what he has done.

Sassen also connects people across the refugee community. He offers to introduce Mengele to Hans-Ulrich Rudel, for whom Sassen sometimes works as a driver and ghostwriter. He and Fritsch visit gatherings at Gerard Malbranc’s residence, where they play poker with other members of the German émigré milieu. In December, Sassen takes Mengele to the Falken, a boat where a password is used to gain entry and guests include prominent European fascists and collaborators. These encounters place Sassen not at the margin of the network but among the people who broker its introductions and social ties.

That network existed within a wider system of escape and refuge. Juan Perón’s government established an Information Office and relied on intermediaries to organize routes through which former Nazis and collaborators reached Argentina. Buenos Aires consequently became a gathering place for exiles from several European fascist movements. Sassen’s contacts and social fluency make him an effective participant in this community, though the evidence presents him primarily through personal connections and journalism rather than as an official in the escape apparatus.

The recordings and Mengele’s refusal

In April 1957, Sassen begins recording sessions at his opulent home. The gatherings take place every Sunday, with men and women assembled around Eichmann as he answers questions from Sassen and Fritsch. The sessions give Eichmann an attentive audience and, as the narrative notes, a setting in which the former Nazi official is flattered by the attention. Sassen’s home thus becomes more than a private meeting place: it is the site of an effort to record and circulate the account of a wanted war criminal.

Sassen tries to bring Mengele into the project, but Mengele refuses. He does not want publicity and regards Eichmann as a liability, warning that the attention could attract danger and reveal the identity behind Eichmann’s alias. This refusal exposes a limit to Sassen’s influence: although he has earned Mengele’s confidence and can gather important figures around a table, he cannot persuade his friend to join the sessions. The difference in their aims is clear. Sassen pursues the interviews and their potential public reach; Mengele wants to avoid notice and concentrate on his own affairs.

Exposure, suspicion, and flight

The capture of Eichmann transforms the meaning of Sassen’s recordings. As the hunt for Nazi fugitives intensifies, former associates suspect that Sassen betrayed Eichmann. The narrative does not establish that suspicion as fact. It does establish that Sassen sells the recorded interviews to Life magazine and to German and Dutch media, receiving substantial attention and commercial value from material created in his home.

He then flees to Uruguay and presents himself as a reformed Nazi. The sequence sharply changes his position within the émigré circle: the journalist who had offered discretion and access becomes a figure suspected of exposing a former associate, while his sale of the interviews makes their circulation an accomplished fact. Sassen’s trajectory shows how the same qualities that made him useful—his facility with words, connections, and access to influential men—could also make him a conduit through which their carefully guarded world reached a wider public. The recordings preserve evidence of that world, but their sale fractures the trust on which Sassen’s own place in it had depended.