Swedish trade policy and Swedish foreign policy were closely linked by the Swedish policy makers. They were painfully conscious that decisions in one could have — and often did have — significant consequences on the other. The standard history of Sweden's trade policy was written by one of its main participants, the diplomatic negotiator Gunnar Hägglöf. Hägglöf made clear that Sweden's policy was to secure vital supplies through negotiated trade agreements with both sides and so one of the requisite skills to achieve this was a delicate balancing act with both parties — referred to as ‘double-negotiation’ — taking care not to disclose or concede perceived advantages to which the other might take exception.

The vital supplies on which Sweden was so dependent were primarily coal, coke, and oil imports because the country has few carbon resources despite extensive forestry. Before the war, coal and coke were imported from Britain which was Sweden's primary trading partner, and oil from the United States. Germany was also an important trade partner. Germany relied on Sweden for about 40 per cent of its supplies of iron from ore which was extracted in the huge Norrland mines of Gällivare and Kiruna. The ore was transported by rail to the port of Luleå on the coast of the Gulf of Bothnia in the ice-free months, and to the port of Narvik on the coast of Norway in the winter months for shipment by sea to ports in Germany. Iron ore was correctly anticipated by the UD to be one of the most contentious issues in a European war.