At the 1955 Geneva conference on the Peaceful Uses of Atomic Energy, one of the busiest luminaries was John Cockcroft. The British head of Harwell was collared by the Argentinean delegation, headed by a naval officer. The Argentineans had previously sought help via diplomatic channels but there was nothing in it for the United Kingdom, whose Cold War remit did not typically extend to South America.
“The Argentinean Delegation told me they would like assistance on a commercial basis on two points,” he filenoted afterward. “I advised them that in principle we were willing to help on a commercial basis and that they should write to Sir Edwin Plowden.” He knew full well that Argentina had already extended diplomatic feelers to Plowden and had been politely rebuffed. The nation never did obtain any help, commercial or otherwise, from Great Britain.
Cockcroft, John. 1955. Note on discussion with the Argentine Delegation at the Geneva International Conference, Aug. 13. AB 6/1414. National Archives, Kew, United Kingdom.