Responding to a request from Michael Palliser (Wilson's Private Secretary for foreign affairs), the Foreign Office's seasoned Europe-watcher Derek Day argued that the government needed to balance three – sometimes conflicting – UK interests. First, there was the position as a European power, particularly with regard to the ongoing EEC application. Second, there was the UK's status as a nuclear power, in which the UK shared “special responsibilities” with the US, exemplified by the UK's acquisition of Polaris submarine-launched ballistic missiles as its primary nuclear deterrent. Third, there was the desire to see a non-proliferation treaty concluded, which sometimes meant disagreement with both the United States and the Soviet Union. Day contended that the United Kingdom seemed to have been successful in positioning itself as understanding European anxieties, with Bonn having congratulated Wilson's administration on bring “good Europeans.” Day's assessment was seen and lauded by Wilson, who hoped that it was correct.

By the early summer of 1967, Foreign Secretary George Brown felt compelled to comment that "if the situation should arise in which there is a direct confrontation between the United States and Russians on one side—and the members of EURATOM on the other, on the issue of the acceptability of EURATOM safeguards we should have to consider our position very carefully: the whole success of our European policy might depend on the choice we made. For the present it should therefore be a major aim of our policy at Geneva to see that things do not reach such a state." This came only a week after Wilson formally launched the UK's bid to become a member of the EEC, and two days after De Gaulle cast doubt on Britain's fitness to join the community.