Editing Battle of the Bulge (section)

==Bletchley Park post-mortem==

===Missed indicators===
At Bletchley Park, [[F. L. Lucas]] and [[Peter Calvocoressi]] of [[Hut 3]] were tasked by [[Archibald Nye|General Nye]] (as part of the enquiry set up by the Chiefs of Staff) with writing a report on the lessons to be learned from the handling of pre-battle Ultra.{{sfn|Annan|1995|p=121}} The report concluded that "the costly reverse might have been avoided if Ultra had been more carefully considered".{{sfn|Hinsley|1993|p=11}}{{sfn|Calvocoressi|2001|pp=61–64}} "Ultra intelligence was plentiful and informative" though "not wholly free from ambiguity", "but it was misread and misused".{{sfn|Bennett|2011|p=179ff}} Lucas and Calvocoressi noted that "intelligence staffs had been too apt to assume that Ultra would tell them everything".{{sfn|Annan|1995|p=121}} Among the signs misread were the formation of the new 6th Panzer Army in the build-up area (west bank of the Rhine about Cologne); the new 'Star' (signals control-network) noted by the 'Fusion Room' traffic-analysts, linking "all the armoured divisions [assembling in the build-up area], including some transferred from the Russian front";{{sfn|Pearson|2011|pp=66–67}}{{sfn|Calvocoressi|2001|pp=61–64}} the daily aerial reconnaissance of the lightly defended target area by new [[Arado Ar 234]] jets "as a matter of greatest urgency"; the marked increase in railway traffic in the build-up area; the movement of 1,000 trucks from the Italian front to the build-up area; disproportionate anxiety about tiny hitches in troop movements, suggesting a tight timetable;{{sfn|Bennett|2011|p=179ff}}{{sfn|Calvocoressi|2001|pp=61–64}} the quadrupling of Luftwaffe fighter forces in the West;{{sfn|Bennett|2011|p=179ff}} and decrypts of Japanese diplomatic signals from Berlin to Tokyo, mentioning "the coming offensive".{{sfn|Smith|2011|pp=270–272}}{{sfn|Bennett|1994|pp=270–272}}

===SHAEF failures===
For its part, Hut 3 had grown "shy of going beyond its job of amending and explaining German messages. Drawing broad conclusions was for the intelligence staff at SHAEF, who had information from all sources," including aerial reconnaissance.{{efn|Calvocoressi to [[Neil Leslie Webster]]{{sfn|Pearson|2011|p=67}}}} Lucas and Calvocoressi added that "it would be interesting to know how much reconnaissance was flown over the Eiffel sector on the U.S. First Army Front".{{sfn|Annan|1995|p=121}} E. J. N. Rose, head Air Adviser in Hut 3, read the paper at the time and described it in 1998 as "an extremely good report" that "showed the failure of intelligence at SHAEF and at the Air Ministry".{{sfn|Smith|2011|pp=270–272}}{{sfn|Millward|1993|p=24}} Lucas and Calvocoressi "expected heads to roll at Eisenhower's HQ, but they did no more than wobble".{{sfn|Bush|2010}}

Five copies of a report by the Chief of the [[Secret Intelligence Service]]{{snd}}''Indications of the German Offensive of December 1944, derived from ULTRA material, submitted to DMI''{{snd}}were issued on 28 December 1944. Copy No. 2 is held by the [[The National Archives (United Kingdom)|UK National Archives]] as file HW 13/45.<ref>{{cite web |title=The Discovery Service |url=http://discovery.nationalarchives.gov.uk/details/r/C5006984 |website=discovery.nationalarchives.gov.uk |access-date=31 August 2018}}</ref> It sets out the various indications of an impending offensive that were received, then offers conclusions about the wisdom conferred by hindsight; the dangers of becoming wedded to a fixed view of the enemy's likely intentions; over-reliance on "Source" (i.e. ULTRA); and improvements in German security. It also stresses the role played by poor Allied security: "The Germans have this time prevented us from knowing enough about them; but we have not prevented them knowing far too much about us".<ref>UK National Archives HW 13/45, "Indications of the German Offensive of December 1944", Part C, para. 5</ref>