Why pay much attention to a small-scale raid on a French port that lasted only one day (August 18–19, 1942) before the attackers were kicked back into the sea? By all measures of size and intention, the Dieppe Raid was nothing like as significant as Walcheren, Gallipoli, or Crete in the history of amphibious warfare; even if it had proven to be successful, it was not intended to go anywhere. Yet while it was certainly not successful, it pointed to many a lesson that British Empire planners still had to learn. It was a badly arranged operation that led to a disproportionate number of casualties, chiefly Canadian. In that setback, ironically, lay its significance: it had the same perverse utility as had the losses in Convoys HX 229 and SC 122 in March 1943 and the appalling USAAF bomber losses during the October 1943 Schweinfurt-Regensburg raids. All three heavy blows dealt by the Germans at the tactical-operational level—convoy escort, strategic air, and amphibious landing—compelled the Western Allies to rethink seriously their previous assumptions and to search energetically for new weapons, tactics, training techniques, and organization.
But Dieppe was somewhat special as compared to the convoys and the bomber raids, which were inherently strategic to begin with. It was always thought of as a test, a trial run against the Atlantic Wall, which the Wehrmacht had been constructing ever since the decision to abandon Operation Sealion in late 1940. This operation was intended to produce lessons that might help preparations for later, greater actions. Many historians have used this utility argument—“the lessons of Dieppe”—as its ultimate justification, while Canadians have been outraged at the idea that the first deployment of their troops in the European theater was as a form of guinea pig in an experiment, and so badly bungled.
The planning and execution of the raid was urged on by Mountbatten’s Combined Operations. They would seize and hold a major enemy-defended port for a short time, gather information, and gain a chance to measure the German reaction. All this made sense militarily, and it also reflected political realities: both Stalin and Roosevelt were pressing for an early opening of a second front in France, the British public was restive at the setbacks in North Africa and the Far East, and the Canadian public was wondering whether their troops would ever be launched into battle. The original operation, code-named Rutter, was actually planned for early July, although, ominously, it was disrupted by a nighttime Luftwaffe attack upon the vessels assembling in the harbor. Renamed Operation Jubilee, it was dispatched across the Channel five weeks later, as the largest combined operation in the region hitherto. Some 6,100 troops were involved, the bulk of them in two Canadian infantry brigades. Most of the obvious features for an amphibious assault were incorporated. There would be aerial protection, a naval bombardment, and two flanking attacks as well as the main assault. The landing craft would also be carrying tanks. The convoy of 250 vessels would be preceded by minesweepers and escorted by destroyers. Specialist forces such as the commandos (plus fifty U.S. Rangers, the first American land troops to fight in Europe, and the first to die) would join in, and the central forces would hit the beaches just before dawn. On paper it looked good. Fair stood the wind for France.
In the middle of the night, the northern flank group bumped into a small German convoy going along the coast and got into a fight with enemy torpedo boats, coming off worse; the German land defenses were thus alerted. Only a small contingent from No. 3 Commando managed to get ashore, climb the cliffs, and snipe at the shore batteries. In the south, No. 2 Commando had a much easier task and carried out its demolitions. In the center, once landed, the main force simply could not get off the beaches, the steep shingle being as much an obstacle as the iron and concrete barriers; the tanks ground to a halt in the pebbles.
The destroyers offshore made little impression upon the German defenses and could not communicate with the troops onshore. The large number of Spitfire squadrons were operating at their extreme range—the opposite of the Battle of Britain conditions—and although part of the plan was to inflict a lot of damage on the Luftwaffe, in fact the opposite happened: the RAF lost 119 aircraft, the German air force only 46. German bombs and shells sank a destroyer and thirty-three landing craft. The Canadians suffered terribly as they tried to scramble back to the sea. Of the 6,100 men dispatched, more than 1,000 were killed and 2,300 captured; many of the survivors came back seriously wounded. About 1,000 troops never had the chance to get ashore. By midmorning it was over.
The literature about the Dieppe Raid has split into two separate categories. The first consists of multiple expressions of Canadian outrage (and not just in books but in movies, songs, and poems) against British military incompetence—not unlike the ANZAC criticisms about Gallipoli, even if the casualties at Dieppe were far fewer. The second argues for the benefits of the tactical-operational analyses of the existing weaknesses in the raiding plan and thus the longer-term benefits of trying it out. Churchill certainly believed it had been worthwhile when he explained this operation in his history of the Second World War. And that unrepentant buccaneer Bernard Fergusson, of Black Watch and the Chindits, whose last amphibious operation was to be the Suez debacle in 1956, concludes his account with these words: “Out of the fire and smoke and carnage on the beaches of Dieppe emerged principles whereby many lives were to be saved, and victory to be won.” A critic might observe that even without Dieppe much was going to be learned from other amphibious operations that would help the D-Day planners—after all, the North African landings were only three months away.
Still, many lessons were learned from the debacle at Dieppe. Intelligence preparations were inadequate, and it seems that Mountbatten and his staff had pushed ahead with their intentions without the Joint Intelligence Committee knowing about them. How could the planners not know that a German coastal convoy would be in the same waters that night, or that German forces along the coasts had been put on high alert, with additional machine gun battalions recently brought in to Dieppe itself ? The strength of the German defenses was not properly measured, nor the nature of the terrain appreciated—how exactly would one get a heavy Churchill tank up a steep pebble beach, and even if the vehicles managed to crest such a rise, how would one get them past solid antitank walls without special equipment? Ship-to-shore movements were clumsy, and few if any of the Canadian commanders had amphibious warfare experience. Landings were late, sometimes in the wrong place. There was no control from offshore, because there was no command ship. Daytime aerial support was inadequate because the RAF did not have full command of the air. There was no preceding heavy bombing by Bomber Command, nor provision made for tactical air strikes. The strength of the naval bombardment was completely inadequate; if 15-inch battleship guns could not make much impact at Gallipoli, why should 4-inch destroyer guns do so off Dieppe? Above all, there was the chief blunder: making the main attack against a heavily held harbor rather than on some less protected part of the coast. If the Allied planners wanted to test the possibilities of seizing a defended port, at Dieppe they got their answer.
But there was something else about the value of the Dieppe experiment that was larger and rather more nuanced, more of a psychological lesson. The second front, whenever it came, was definitely going to take place along the Atlantic-swept waters of France and against well-trained German troops. That was a combination of challenges that really had to be tested. If the results of the raid confirmed all of Alanbrooke’s worries—and supplied him and Churchill with the ammunition to argue for postponing Operation Overlord through 1943 and into 1944—it also presented the Anglo-American planners with a new and much higher benchmark. When, eventually, they did come ashore in France to pursue a full invasion, they were going to have to be very, very good.
That was so, of course, for one further worrying reason. Although well emplaced, the German garrison in and around Dieppe was actually not very large. The 571st German Infantry Division had around 1,500 men in the area, but only 150 of them were there to pour fire onto the main beaches; yet that, with the defensive works, turned out to be enough (again, one thinks of Cartagena de Indias in 1741). The Atlantic Wall would never again be so minimally held, and the next two years would see more and more German divisions moved to that front and fantastically more obstacles, pillboxes, and minefields put in place. In sum, each side could learn much from what had really been a small-scale operation at Dieppe.