Editing Double-Cross System (section)

== V-weapons deception ==
{{see also|Operation Crossbow}}

The British noticed that, during the [[V-1 flying bomb]] attacks of 1944, the weapons were falling {{convert|2|–|3|mi|km|abbr=on|sigfig=1}} short of [[Trafalgar Square]], the actual [[Luftwaffe]] aiming points such as [[Tower Bridge]] being unknown to the British.<ref name= Ordway /><ref name = Irving /> [[Duncan Sandys]] was told to get MI5-controlled German agents such as [[Eddie Chapman|''Zig Zag'']] and [[Wulf Schmidt|''Tate'']] to report the V-1 impacts back to Germany.<ref name = Ordway /> To make the Germans aim short, the British used these [[double agent]]s to exaggerate the number of V-1s falling in the north and west of London and to underreport those falling in the south and east.<ref name = Masterman/><ref name=jones />{{rp| ch 44}} Around 22 June, only one of seven impacts was reported south of the Thames, when {{frac|3|4}} of the V-1s had fallen there. Although the Germans plotted a sample of V-1s which had radio transmitters, showing that they had fallen short, the telemetry was ignored in favour of the agents' reports.<ref name = Irving/>

When the Germans received a false double cross V-1 report that there was considerable damage in Southampton—which had not been a target—the V-1s were temporarily aimed at the south coast ports. The double cross deception had caused a "re-targeting" from London, not just inaccurate aiming. When V-1s launched from [[Heinkel He 111]]s on 7 July at Southampton  were inaccurate, British advisor [[Frederick Lindemann, 1st Viscount Cherwell|Frederick Lindemann]] recommended that the agents report heavy losses, to save hundreds of Londoners each week at the expense of only a few lives in the ports. When the Cabinet learned of the deception on 15 August, [[Herbert Morrison]] ruled against it, saying that they had no right to decide that one man should die while another should survive.<ref name=Irving/> However [[Reginald Victor Jones|R. V. Jones]] refused to call off the plan absent written orders, which never came, and the deception continued.<ref name=jones />{{rp|p. 422}}

When the [[V-2 rocket]] "blitz" began with only a few minutes from launch to impact, the deception was enhanced by providing locations damaged by bombing, verifiable by aerial reconnaissance, for impacts in central London but each "time-tagged" with an earlier impact that had fallen {{convert|5|–|8|mi|km|abbr=on|sigfig=1}} short of central London.<ref name=Ordway/>  From mid-January to mid-February 1945, the mean point of V-2 impacts edged eastward at the rate of a couple of miles a week, with more and more V-2s falling short of central London.<ref name=Masterman/>  Of the V-2s aimed at London, more than half landed outside the London Civil Defence Region.<ref name=jones />{{rp|p. 459}}