The crushing defeats the Allies suffered since 1939 were beginning to take their toll on Allied morale. Even though the Battle of Britain had staved off German victory, little success had happened since then.
Most of occupied Europe had been under Nazi domination for at least two years. While there was no immediate threat of the Allies losing the war, the Allied command, especially the British, wanted to win a battle in order to raise morale at home and abroad.
During the Battle of Britain the United Kingdom mobilized armies and brought them to England to drive off the expected invasion. While most units were too late to be a factor in dissuading the Germans for attacking, the armies did remain in case they were needed. One such unit was the Canadian 2nd Division. Landing in England in 1940, they were training for two years without seeing combat. The men were restless, sick of endless training and bad food.
Meanwhile, a young officer took command of new force called Combined Operations. A hero in the Battle of Crete, Lord Louis Mountbatten, was tasked with developing missions that would test the new doctrine of amphibious landings. Directing massive air, sea, and land forces, Mountbatten’s staff had no idea of what to do with them. Should they land in France and hold a port to see if the real invasion should land there? Should they conduct reconnaissance-in-force missions to test German defenses? The lack of a clear mission hampered planning as Combined Operations was unsure of its own mission. Mountbatten, flamboyant, famous before the war as a grandson of Queen Victoria, did not intend to fail at his mission, whatever it was.
These three events collided in the surf of the little French port of Dieppe. With limited port facilities, Dieppe was close the English coast in the Pas-de-Calais. An important consideration was the distance of Dieppe from English airfields. Fighters could cover the operation without running out of fuel prematurely.
Finally Combined Operations outlined the plan: A small force, mostly Canadian 2nd Division soldiers but with Royal Marines and 68 US Army Rangers making the US European ground combat debut, would seize Dieppe and hold it for forty-eight hours. The RAF would engage and destroy the German opposition in the air to reduce the German Luftwaffe.
Almost from the start Combined Operations doomed the plan and the men that would carry it out. Reconnaissance was incomplete, and did not reveal the extent of the German defenses, which included an underwater minefield, many coastal guns, and airfields and reinforcements that could bolster the town’s garrison. The regular passage of E-boats, German patrol boats armed with guns and torpedoes, was not noted.