Who won World War II due , in part , to the contributions of breaking the Enigma code ?
The third explanation is given by Winterbotham , who recounts that two weeks after V - E Day , on 25 May 1945 , Churchill requested former recipients of Ultra intelligence not to divulge the source or the information that they had received from it , in order that there be neither damage to the future operations of the Secret Service nor any cause for the Axis to blame Ultra for their defeat .