What evidence does this historian give for his belief that hitler would not have been stopped prior to 1939?

Neither the general population nor the administration of Britain and France was molded to war. This isn't valid. Roosevelt had been utilizing promulgation in the United States to turn general sentiment against Hitler, setting the phase for war as right on time as 1937. There would have been a close correspondence between the US, Britain, and France over what was happening, so Britain and France were, truth be told, get ready for war away from public scrutiny.