The British Ambassador (Lothian) to President Roosevelt


The British Government have informed me that they would greatly appreciate an immediate and general interchange of secret technical information with the United States, particularly in the ultra short wave radio field.

It is not the wish of His Majesty’s Government to make this proposal the subject of a bargain of any description. Rather do they wish, in order to show their readiness for the fullest cooperation, to be perfectly open with you and to give you full details of any equipment or devices in which you are interested without in any way pressing you beforehand to give specific undertakings on your side, although of course they would hope you would reciprocate by discussing certain secret information of a technical nature which they are anxious to have urgently.

I presume that, if you approve in principle of this interchange of information, you would wish to discuss it further with the War and Navy Departments before giving a decision, and, should you so wish, I would be glad to place my Air Attaché and the scientific assistant to the Air Attaché at the disposal of the staff of the C. G. S. (General Marshall) and the C. N. O. (Admiral Stark) with a view to their discussing what technical matters might be of interest to these Services.

As to subsequent procedure, should you approve the exchange of information, it has been suggested by my Government that, in order to avoid any risk of the information reaching our enemy, a small secret British mission consisting of two or three service officers and civilian scientists should be despatched immediately to this country to enter into discussions with Army and Navy experts. This mission should, I suggest, bring with them full details of all new technical developments, especially in the radio field, which have been successfully used or experimented with during the last nine months. These might include our method of detecting the approach of enemy aircraft at considerable distances, which has proved so successful; the use of short waves to enable our own aircraft to identify enemy aircraft, and the application of such short waves to anti-aircraft gunnery for firing at aircraft which are concealed by clouds or darkness. We for our part are probably more anxious to be permitted to employ the full resources of the radio industry in this country with a view to obtaining the greatest power possible for the emission of ultra short waves than anything else.