Aiken drafted in additional personnel to the Irish Mission to the UN in the run-in to the XVIth UN Session. Seán Ronan, the head of the political and information divisions at headquarters in Dublin, was sent as a delegate to the First Committee of the UN, involving him intensely in Aiken’s non-dissemination efforts. His insider account reveals some of the dynamics and calculations at play in the building, as Ireland managed a balancing act of engineering consensus between East and West. In large part, the Irish Mission crafted the resolution’s language to skirt the issue of alliance nuclear sharing in a bid to manufacture unanimity. The Irish had pondered co-sponsoring a Swedish draft resolution but anticipated that it would face resistance from NATO comparable to earlier iterations of the Irish resolution. Similarly, Ireland neglected to mention a proposed new disarmament committee in the draft resolution – there was no guarantee that it would form and report expeditiously. Finally, by drawing on the instrument of acclamation, the Irish sidestepped French objections and gained universal approval for Resolution 1665 (1961), wrapping the resolution in universal legitimacy. 

Aiken’s first step was a modest paragraph calling for the formation of a UN commission to recommend measures to the next session. However, global attentions were focused on nuclear tests and their health effects, so Aiken linked his initiative with the American-led seventeen-power resolution requesting all states to suspend testing voluntarily. Aiken proposed an amendment to that motion that included the notion of brokering an understanding between nuclear weapons powers and non-nuclear powers.  He submitted that the former voluntarily desist from supplying nuclear weapons to other countries, while non-nuclear powers reciprocated and volunteered not to develop such weapons during a test suspension. This proposed quid pro quo became a staple in the Irish resolutions subsequently and eventually be inscribed into the NPT.

Aiken’s speech invoked recognizable tropes such as a ‘geometric’ increase in nuclear powers, creating an urgent need to halt the spread. His speech was seminal in identifying themes he and international opinion would rehearse in future years. He conjured up fears about small states and revolutionary groups with a bomb acting as ‘the detonator for world-wide thermonuclear war’. Aiken was perceptive – he expected criticisms about institutionalized equality between states (nuclear “haves” and “have nots”), harms to alliances, the sufficiency of test bans, and the absence of monitoring. He sought to disprove the validity of such critiques, and these issues were worked through gradually, eventually leading to the finalization of the NPT ten years later.  

Two "Notes for the Record" from March 1, 1967, describe the vigorous discussions between senior UK government figures, including Harold Wilson, Foreign Secretary George Brown, Minister of State for Foreign and Commonwealth Affairs Lord Chalfont, and chief scientific adviser to the government Solly Zuckerman. Brown argued that "our posture on the matter should be distinctively European rather than one of supporting the United States against other European countries." Wilson was even more explicit, stating that "our approach should be that of a European power discussing the matter with European partners and not seeking to fight American battles." Wilson was keen to let Washington take the lead so that his government might avoid upsetting the French, as had happened with the debates over De Gaulle's 1966 withdrawal from the NATO command structure.