Viewed from the German Democratic Republic (GDR), the Kingdom of Sweden - just a short ferry ride away - seemed somehow to stand apart from the ideological rift that divided much of Europe.
Though Sweden was partly seen as yet another nation grown fat on the spoils of industry, East German officials could also observe in the country the growth of strong trade unions and the increasing redistribution of wealth.
While many Swedes argued passionately for the country to throw its weight behind the United States and its allies, a concurrent radicalization of left-wing movements gave rise to a groundswell of sympathy for the USSR and its satellite states in Central and Eastern Europe.
The high level of interest in international socialism among sections of the Swedish populace intrigued the East Germans, causing them to believe that Sweden might feasibly provide fertile ground for good diplomatic relations with a highly esteemed western nation. This assessment proved to be correct. Sweden extended diplomatic recognition to the GDR in 1972, paving the way for new trade agreements between the two states.
Tore Forsberg, who spent thirty years working for Swedish security service Säpo, recalls the mood in Sweden at the time.
"The average man on the street did not grasp that the GDR was a brutal dictatorship. I think we Swedes have a tendency to be a bit naive," he tells The Local.
"People didn't always differentiate between the GDR and the Federal Republic. The left in Sweden, including many Social Democrats, pushed hard for improved diplomatic relations with the East Germans," he adds.
Writing about the 'König' spy affair in the summer of 2000, Sweden's current foreign minister Carl Bildt went a step further.
"German dictatorships have at various times caused Swedes to show their dedication. There were those who were dedicated to the brown dictatorship quite some time ago, and there were those who were dedicated to the red dictatorship not so very long ago," he wrote.
But while Sweden may have offered scope for the recruitment of true believers, it was the country's openness that was most inviting. As border security was less stringent than elsewhere in Europe, Sweden became a popular meeting place for Eastern Bloc spies based in Europe's NATO member states. Intelligence agencies from the USSR, GDR, Czechoslovakia, Bulgaria and Poland all quickly established a presence in the Swedish capital.
"If you were in Sweden you could travel anywhere freely. The country also made up half the border between East and West," says Forsberg.
"Stockholm in particular became something of a spy playground and was - together with Lisbon and Casablanca - one of the three major spy capitals in this part of the world."
From an East German perspective, Sweden was of particular interest to the Hauptverwaltung Aufklärung (HVA), the Stasi subdivision responsible for foreign espionage. The organization was, for example, well-represented at the East German embassy in Stockholm.
But the HVA's activities were being monitored more closely than they could ever have imagined.
"Säpo had excellent cooperation with other agencies and it was also running a very successful entrapment scheme. By making good use of a double agent, Säpo was able to intercept a lot of correspondence," intelligence expert Joakim von Braun tells The Local.
In his book 'Spioner och spioner som spionerar på spioner'*, Tore Forsberg describes the classic Romeo and Juliet spy story that led to the exposure of former HVA chief Marcus Wolf, who until that time was known as ‘the man without a face',
For thirty years Wolf had successfully avoided detection by the international intelligence community. But with the help of a well-placed 'Juliet' - a Swedish woman of German descent whom the East Germans believed to have fallen for one of its Romeo spies - Säpo managed to acquire a photograph of the HVA chief during one of his trips to Stockholm.
The picture of Wolf was made available for publication in Germany and placed on the front cover of Der Spiegel, leaving the wily spymaster with little option but to rethink his strategy.
"I actually met him when he came to Stockholm after the collapse of the Soviet system. He asked me how 'little old Sweden' always seemed to know so much about his agency," says Forsberg.
"When I told him about our Juliet he banged his fists on the table and said: 'You can't trust anyone!'"
*The book's title translates as 'Spies and spies who spy on spies'.