I have to respectfully disargee with your assessment of Patton's responsibility for choosing the Sherman over the Pershing. Whether or not the Pershing could have been ready for D-Day, the choice to go with the Sherman was Patton's and Patton's alone. It was the wrong choice, for the wrong reasons. Patton's rationale, on the papers from the Tideworth Down commission, as quoted by Belton Cooper (which unless he is lying in print, I am ready to believe, particularly since, when I read Patton's memoirs, I felt he was less than forthcoming), was "under our doctrine, tanks don't fight tanks, tank destroyers fight tanks". Tell that to the Germans, apparently they were unaware of our doctrine. I don't know the first thing about the R&D process in the U.S. Millitary at that time, but I do know that before the M1A1 Abrams, we never sent our troops to war with the best armored vehicles (the development of the Bradley Fighting Vehicle being a recent example of our poor R&D). If I seem a little bitter about this choice, it is because way too many good men died as a result. I have never heard an allied tanker who fought a Sherman against a German Tank speak well of the model. I also know that by April, 1945, even despite theTidesworth Downs decision to put the Pershing on the back burner, 9 Pershings were put into service. If this is the case, I think that the opinion of your source that the Pershing could not have been ready for service 10 months earlier if all of our resources had been put behind our production is questionable. Even assuming the Sherman couldn't have been ready for D-Day, it would have been mighty helpful in the drive across France and Holland, and the Sherman was as helpless against the superior german Panthers and Tigers as using the stop-gap M3 Grant/Lee for an extra couple of months would have been. I could be wrong, and the fault might not lay with Patton, but who ever put our troops into Battle against the Panzer IV longbarrel, Panther and Tiger should have been court martialed.