From Defeat in the West, by Milton Shulman (Secker & Warburg, 1947; Dutton, 1948; Arcadia, 2017), Kindle Loc. 1052-72, 1226-39:
Up until now victory had tumbled upon victory in breathless profusion. Now was time for defeat. Hitler suffered his first at Dunkirk. And what better authority for this statement than von Rundstedt himself.
“To me,” remarked the Field Marshal rather ruefully, “Dunkirk was one of the great turning-points of the war. If I had had my way the English would not have got off so lightly at Dunkirk. But my hands were tied by direct orders from Hitler himself. While the English were clambering into the ships off the beaches, I was kept useless outside the port unable to move. I recommended to the Supreme Command that my five panzer divisions be immediately sent into the town and thereby completely destroy the retreating English. But l received definite orders from the Fuhrer that under no circumstances was I to attack, and l was expressly forbidden to send any of my troops closer than ten kilometres from Dunkirk. The only weapons I was permitted to use against the English were my medium guns. At this distance I sat outside the town, watching the English escape, while my tanks and infantry were prohibited from moving.
“This incredible blunder was due to Hitler’s personal idea of generalship. The Fuhrer daily received statements of tank losses incurred during the campaign, and by a simple process of arithmetic he deduced that there was not sufficient armor available at this time to attack the English. He did not realize that many of the tanks reported out of action one day could, with a little extra effort on the part of the repair squads, be able to fight in a very short time. The second reason for Hitler’s decision was the fact that on the map available to him at Berlin the ground surrounding the port appeared to be flooded and unsuitable for tank warfare. With a shortage of armor and the difficult country. Hitler decided that the cost of an attack would be too high, when the French armies to the south had not yet been destroyed. He therefore ordered that my forces be reserved so that they could be strong enough to take part in the southern drive against the French, designed to capture Paris and destroy all French resistance.”
Hitler’s successes as a strategist were now beginning to bear their blighted fruit. Despite the assurance of a man like von Rundstedt that he was capable of carrying on against the English at Dunkirk, his opinion was tossed aside by the Fuhrer in favor of his own judgment and intuition. Thus a little man studying a map hundreds of miles away from the battle, by rejecting the advice of his most brilliant commander, changed the course of history. The ‘miracle of Dunkirk’ seems even more fore-ordained than it ever appeared before.
“Hitler’s order preventing us from attacking the English at Dunkirk convinced many of us that the Fuhrer believed the English would come to terms,” said Blumentritt, “I have spoken to some Luftwaffe officers and they also say that Hitler forbade them from conducting an all-out aerial attack against the shipping at Dunkirk. This attitude of the Fuhrer’s was made clear to me at a round-table conference he had with a small group of officers following the break-through into France. It was at Charleville when Hitler came to visit Army Group headquarters. He was in an expansive mood and discussed with us his political ideas of the moment. He told us that he was exceptionally pleased with the way the offensive was going, and that everything had worked out beyond his wildest expectations. Once France was defeated there was only England left.
“Hitler then explained that in his opinion there were two fundamental established institutions which, for the time being, must be recognized as essential cornerstones in the framework of Western civilization — the Catholic Church and the British Empire. The power and strength of these two forces must be accepted as faits accomplis, and Germany must see that, for the moment, they be maintained. To achieve this purpose he proposed to make peace with England as soon as possible. Hitler was willing to grant England most generous terms, and he would even desist from pressing his claims for German colonies. Of course, England’s armed forces would have to be disbanded or seriously decreased in size. But in return for such a concession, Hitler was prepared to station as many as ten German divisions in England to aid the British government in maintaining the security of the United Kingdom. Having heard these theories of the Fuhrer, we can hardly be blamed for believing that the invasion of England was never contemplated as a serious operation.”