Layout 8 - Winston Churchill

British Military Intelligence commented on this decrypt:“Although there are a number of possible reasons forthis order, it cannot be overlooked that it may be in connectionwith the movement of troops and armament forinvasion purposes.” 1Throughout the autumn and winter of 1940, thesearch for indications of a German invasion remained thetop priority of the Bletchley eavesdroppers. On 10 October1940, Churchill was shown summaries of decrypts ofGerman Air Force top-secret signals that had revealed,among other German instructions, the appointment in thefirst week of October of German Air Force officers to theembarkation staffs at Antwerp, Ostend, Dunkirk andCalais, where air reconnaissance—another indispensablearm of Intelligence—revealed the presence of what couldwould well have been invasion barges.Top-secret instructions had also been decrypted atBletchley with regard to a German air formation headquarters,which was known to be in charge of German Air Forceequipment in Belgium and Northern France, “settling thedetails of loading of units and equipment into ships.” On24 September 1940 the German Third Air Fleet receivedorders, also decrypted at Bletchley, concerning the supply ofair/sea rescue vessels by seaplane bases off Norway and alongthe North Sea and Channel coasts “in connection,” as themessage sent to Churchill explained, “with the Seelöwe (SeaLion) operation,” presumed to be the invasion of Britain.On 9 October 1940 a further decrypt revealed that onthe previous day the headquarters of the Second GermanAir Fleet “asked for provision of two tankers each filled withapproximately 250,000 gallons of aviation fuel to be held inreadiness for S+3 day (presumably the third day of invasionoperations against UK) at Rotterdam and Antwerp.” 2It was not until 12 January 1941 that Churchillreceived the details of an Enigma decrypt that German AirForce wireless stations on the circuit of the air formationheadquarters responsible for German Air Force equipmentin Belgium and Northern France—equipment that wasknown to have been on standby for invasion duties—was“no longer to be manned as from January 10.” 3The danger of invasion was over. Other decrypts werenow making it clear that the new German focus of militaryand air preparations was against its ally and partner of theprevious sixteen months, the Soviet Union. 4Churchill’s VigilanceAs Prime Minister and Minister of Defence, Churchillwas intensely concerned with maintaining the secrecy of allaspects of war policy and planning. In no area was secrecymore important to him than with regard to Enigma.On 16 October 1940 he wrote to General Ismay, headof his Defence Office: “I am astounded at the vast congregationwho are invited to study these matters. The AirMinistry is the worst offender and I have marked a numberwho should be struck off at once, unless after careful considerationin each individual case it is found to beindispensable that they should be informed. I have addedthe First Lord, who of course must know everything knownto his subordinates, and also the Secretary of State for War.”Churchill continued: “A machinery should be constructedwhich makes other parties acquainted with suchinformation as is necessary to them for the discharge of theirparticular duties. I await your proposals. I should also addCommander-in-Chief Fighter and Commander-in-ChiefBomber Command, it being clearly understood that theyshall not impart them to any person working under them orallow the boxes to be opened by anyone save themselves.” 5Within three weeks of Churchill’s minute to Ismay,the number of recipients of Enigma-based material hadbeen fixed at thirty-one.Churchill’s vigilance was continual. In September1941, on reading the wide circulation given to a 7 a.m.summary of a series of decrypts giving the movement ofGerman fuel ships in the Mediterranean between Naplesand the North African port of Bardia, he wrote to BrigadierStewart Menzies, Chief of the Secret Intelligence Service(MI6), and to the Army and Navy Chiefs of Staff: “Surelythis is a dangerously large circulation. Why sh[oul]d anyonebe told but the 3 C-in-Cs. They can give orders withoutgiving reasons. Why should such messages go to subsidiaryHQs in the Western Desert.” 6When Churchill travelled outside London and overseas,the summaries and assessments of Enigma decryptswere sent on to him by courier or top-secret radio signal. >>“When Churchill travelled outside London and overseas, the summaries andassessments of Enigma decrypts were sent on to him by courier or top-secret radiosignal. When he was in Britain, translated summaries of the decrypts, and theBletchley assessments, were sent him in locked buff-coloured boxes to which healone had the key. None of his Private Office knew what the contents were.”FINEST HOUR 149 / 21