810.74/611: Telegram
The Ambassador in the United Kingdom (Winant) to the Secretary of State
[Received 10:25 p.m.]
6368. Reference Department’s 5240,5 5241, 5242, October 23, 4 p.m.6 5407 October 29, midnight, and 5528 November 5, 3 p.m.7 Foreign Office states that if all wireless messages in code were prohibited and attempts were then made by the Axis to send telegrams in code by cable the British authorities would be able to control these telegrams. Foreign Office points out in this connection that British cable communications between Buenos Aires and the Axis go by way of Portugal and London and that telegrams of the Axis could be stopped in London.
With reference to telegrams from one neutral to another neutral Foreign Office says that it assumes that we would not wish the British authorities to attempt to stop them. British authorities of course would, Foreign Office adds, exercise control over telegrams to the Axis en clair. Foreign Office also assumes we would be able to stop any Axis messages if the attempt were made to send them over cables on the West Coast.
Foreign Office sums up British view as follows: British authorities would be glad to see all code messages by radio prohibited or, in case this is not found to be feasible, they would be glad to see all radio code messages sent to or received from non-American countries, as in the case of Chile, prohibited.
Under no circumstances the Foreign Office emphasizes would the British authorities agree to the prohibition of their cable code message. If this were attempted by the Argentinians the British authorities, according to the Foreign Office would throughout the British Empire take retaliatory measures against Argentina.
No part of the foregoing has been repeated to Buenos Aires.