In a BBC post from a few years back, Julian Thompson looks at the Dieppe raid:
On 19 August 1942, a disastrous seaborne raid was launched by Allied forces on the German-occupied French port of Dieppe. Why was such a raid ever undertaken? Because, with Germany operating deep in the Soviet Union, the Russians were urging the Allies to relieve the pressure on them by opening a second front in north-west Europe.
At the same time the British Chief of Combined Operations, Rear Admiral Louis Mountbatten, was agitating for a practical trial beach landing, against real opposition, for his troops. In the face of this pressure, Churchill decided that Operation Rutter, a ‘hit and run’ raid on Dieppe, should go ahead.
Churchill and the Chiefs of Staff — the heads of the Navy, Army and Air Force, who met daily to discuss strategy and advise Churchill — were responsible for this disastrous misjudgement. But, because no written record exists of the Chiefs of Staff approving the raid in its final form, it has sometimes been suggested that it was really Mountbatten who remounted it without authorisation. This is almost certainly nonsense.
The Chiefs of Staff disliked Mountbatten, regarding him as an upstart foisted on them by Churchill, so any unauthorised action on his part would have given them the ammunition to recommend his removal. Since Mountbatten was not removed, and the Chief of the Imperial General Staff, General Sir Alan Brooke, in his frank and detailed diary, makes no mention of his having exceeded his authority, it seems unlikely that Mountbatten can be accused of mounting the raid without authority.
General Brooke was in the Middle East from 1 August 1942, returning on the 24th, after the event. This was unfortunate, for, as the most forceful and intelligent of the Chiefs of Staff, had he been in Britain in the days preceding the raid, he might have persuaded Churchill to call it off.
Much has been said since about the fact that the Dieppe raid was a necessary precursor to the great amphibious operations that were to follow, in terms of the lessons learned and experience gained. Mountbatten pursued that line all his life. But as Chief of Combined Operations, he did bear some of the responsibility for mounting the operation, so one can only comment, ‘he would say that, wouldn’t he?’
The disaster did point up the need for much heavier firepower in future raids. It was recognised that this should include aerial bombardment, special arrangements to be made for land armour, and intimate fire support right up to the moment when troops crossed the waterline (the most dangerous place on the beach) and closed with their objectives.
However, it did not need a debacle like Dieppe to learn these lessons. As judged by General Sir Leslie Hollis — secretary to the Chiefs of Staff Committee and deputy head of the Military Wing of the War Cabinet with direct access to Churchill — the operation was a complete failure, and the many lives that were sacrificed in attempting it were lost with no tangible result.