In the spring of 1939, some months before the Second World War, the Swedish Pavilion opened its doors at the World Exhibition in New York. Enthusiastic people - the American press hailed the Pavilion as a symbol of human civilisation - could taste the pickled herring from a rotating smorgasbord and ponder on a multi-meter high wooden horse. But they were also met by a large portrait of Per Albin Hansson, the Sweden’s Social Democrat prime minister, and a greeting from the man who had conquered the welfare from the Right and filled it with progressive content:

Visitors will find a country where different communities work together to further social progress in order to make the ideal of democracy a reality, so that Sweden, in peace and freedom, can become a real national home for all of its people.

The formulation of cooperating groups was the focus of the message. For a few years in the 1930s, Sweden appeared to constitute a promising have...