Shortly after noon on 9 November 1964, Jens Otto Krag, the Danish prime minister and leader of the Social Democrats (SD), arrived in Downing Street to meet his British Labour counterpart Harold Wilson. The gathering came at a low point in Britain's international standing. Just a fortnight earlier, faced with a balance of payments crisis, the new Labour government had chosen to impose a 15 per cent surcharge on all goods imported into Britain except food, tobacco and raw materials. The problem of course was that the surcharge breached London's obligations in the General Agreement on Tariffs and Trade (GATT). And, as Krag was at pains to stress, it also contravened the rules governing the European Free Trade Association (EFTA), the grouping of seven countries centred on Britain. The Danish, for their part, were major exporters of agriculture, one of the few product types exempted from the measure. The economic effect of the surcharge was hence likely to be negligible. But this did not stop Krag from pointing out the broader political repercussions. As he drily put it in his meeting with Wilson, ‘Britain was the major partner in EFTA, and one of the great attractions for the smaller countries was the prospect of an open market in Britain […] but the import surcharge had dealt a heavy blow to the whole EFTA concept’. The widespread assumption that the interests of the Seven were best served by a close strategic partnership with Britain had been seriously undermined.

Such remarks were all the more powerful, and unnerving, for coming from one of Britain's closest and most steadfast European allies. That still in the 1960s the Anglo-Danish relationship was widely considered along these lines should not have come as a complete surprise. In terms of politics alone this was a nexus almost unrivalled in Western Europe, both countries sharing a preference for looser forms of international cooperation and free trade, intimate security and military ties and a position on Europe's geopolitical periphery. Relations were most deeply shaped by economic considerations, however. Dry statistics about agricultural exports symbolise in particular quite how far Denmark was financially dependent on its larger neighbour. One of the starkest is that of the 44 per cent of foodstuffs which travelled across the North Sea in 1950, double that of Denmark's next four largest markets combined.