Did the Mechelen Incident help cause the Fall of France?

[Pericles]

Just in case people reading this thread don't know, here is the basic info about it. Essentially, in early 1940 the original Nazi war plans accidentally fell into Belgian hands. It seems that those plans would have had the bulk of the Nazi force go through northern Belgium, where the Allies ended up expecting them. Afterwards, the Nazi war plan was changed to the tragically successful attack through the Ardennes.

I'm not an expert on this subject, so I'd be interested in seeing whether you think this small PoD was actually important? Did this incident cause the change in the war plan, or would the OTL plan have been adopted anyway? And secondly, if the Nazis stuck to the original plan, would they have still been successful on the Western Front? I've seen a lot of posts here that the Fall of France had a lot of good luck for the Nazis and incompetence by the Allies. So, what happens if the offensive did fail, is it a WWI style stalemate? And does that mean that Nazi Germany is defeated a lot quicker and without so much suffering?

 

[Carl Schwamberger]

Short answer is no and yes. Unless Hitler actually does order the January offensive executed. Hitler had actually been waffling on the decision & agreed with postponement multiple times before. Odds are he accepts any of the other reasons to delay & reschedule.

No one within the German leadership was confident in any of the current plans, including Hitler. He felt pressure to attack while the Allies we're relatively weak, but he & the rest were aware of serious weakness in the Wehrmacht. The idea of postponing until the good weather in May had been on the table for some time.

Odds are the January attack would have been canceled and the preparations continued through April. Had it been ordered forward odds are it would have been a tactical victory at best. A tactical or operational defeat is not out of the question.

Recommended reading:

Seeds of Disaster' Doughty.

Strange Victory' Mays has the most complete description of the evolution of the Sickle cut plan in English.

To Lose a Battle' Horne

The Breaking Point' Doughty

Why France Fell' Chapman

The Fall of France' Jackson

 

[Major Major]

It contributed to Allied overconfidence. A significant reaction was that it was an elaborate deception intended to fool the Allies into a disadvantageous deployment.

 

[Carl Schwamberger]

The Mechelen Incident lacks a lot of context in the English language histories. The above named sources have some background on French thinking surrounding it, but a lot is missing. Among other things there is a largish hole in the details of French intelligence at the time and the information or interpretation they had. They were accumulating from multiple sources a understanding of the German deployments in 1939-1940. The influence of all that is poorly described. That is to say the Mechelen Incident was just a part of a larger picture & possibly not the most influential at the moment.

It contributed to Allied overconfidence. A significant reaction was that it was an elaborate deception intended to fool the Allies into a disadvantageous deployment.

That was one explanation offered up. Its not clear to me if Gamelin or Georges bought off on that one. I'd have to agree Gamelin kept up the appearance of overconfidence right up to his replacement 20 May. Georges alternately did suffer some sort of breakdown in the first week suggesting a lack of confidence. Ditto for Corap. The 9th Army commander did not waste much time attempting a retreat back to the French frontier. I can go on, but the actions of the majority of the French and British commanders in that critical first week suggest a lack of confidence. The exception might be Gamelin, and he had control of the key decisions, such as execution of the Escaut Plan or the Dyle Plan, or the general form of those plans.

The deception explanation also gives the Germans a lot of credit for skill they actually lacked in those years. Compared to other nations or armies their deception ops were relatively weak. Much is made of the 'Matadors Cloak' aspect of the Sicklecut maneuver. What is ironic is that was a concept worked out by pedestrian army staff officers like Halder, Rundsteadt, & Manstein & not the Abwehr, SS or other nazi regime golden boys.

 

[Carl Schwamberger]

Just in case people reading this thread don't know, here is the basic info about it. Essentially, in early 1940 the original Nazi war plans accidentally fell into Belgian hands. ...

This is one of the reasons why reading Mays, or Horne is important. 'Original Plan' in the context of plan yellow had long been discarded. In October 1939 Halder insisted the current plans be discarded & replace ASAP. To that end he directed a series of tests as map exercises starting 7 November to examine a wide set of options. Specifically for the 7th November exercise he ordered three concepts tested. One was the schwerpunkt or mass of maneuver on the Belgian plain, second was with the Schwehrpunckt in the Ardennes, third with no specific schwehrpunckt. Rather a large reserve held back from a general advance and committed as the battle developed. All three plans failed in this initial test. Note that this was the origin of the 'MansteinPlan'. As Chief of staff for Army Group A he was responsible for detailing the actions of AG A in all three scenarios. In the Ardennes schwehrpuckt option he placed the single Panzer Corps available to AGA in the lead and crossing the Meause River in advance of the infantry. A few weeks later he received his expected promotion and appointment to command a infantry corps & his role in planning ceased.

Halder & Hitler were both unhappy with the poor prognostications and Halder kept the OKW staff, and the Army Groups, Armies, and Corps staff busy through the winter refining and testing multiple plans. These test exercises were both on the maps or game table, and in the field as part of the frequent training events that winter and spring. As the armored force increased to ten Panzer divisions and five motor rifle divisions the variations of the plans leaned increasingly on a massed armored group in accordance with Guderians ideas, supported by his followers and allies such as Kliest. While none of the repeated exercises resulted in a decisive or strategic victory those featuring the Ardennes schwehrpunckt were more likely to result in a tactical victory. Seizing on that thin result both Halder and Hilter put the majority of their attention to developing that option. The Mechelen Incident did turn Hitlers attention away from other plans to the Ardennes, but it had been on the table since the directive for the 7th November war-game. March 1940 seems to be the moment Hitler finally committed to the Ardennes option, tho he continued to waffle right up to late May after the battle started. I'm unclear on when Halder came to favor it over the other plans. It may have been as early as January, or as late as March.

Of all the German commanders only a few like Kliest and Guderian developed any real confidence in the Sicklecut plan. For those like Halder, Rundsteadt and most others it was more of a act of desperation, they could not see any better option. Mostly they saw a risky gamble that could very well fail, but all the other ideas tested failed worse. Hitler contrary to myth was not firmly wedded to any specific plan. He kept wavering from one idea to another, loathe to be trapped in a risky venture that had a very unpredictable outcome. After the attack started Hitler kept having crisis of confidence and tried to talk Halder and Rundsteadt into altering the plan on the 12th, 14th, 16th, and 18th May. He was described as increasing fearful the armored corps would be destroyed by Allied counter attacks.

 

[Pericles]

So, the Ardennes plan would have been adopted anyway and the Mechelen Incident wasn't much of a factor in their planning? That's a shame, it would be a good story, but history isn't that simple. It's interesting that the war games all suggested the offensive would fail. Was the big mistake then that the Allies made running into Belgium?

 

[Starslayer_D]

A big point in making the ardennes sicklecut succesfull was that the allies actually moved in the best way to gurantee its success with the dyle plan, by putting their divisions into the pocket. Aslo, Guderian adn Rommel driving their panzer groups forward to the channel despiteorders to be more cautious ensured te germans cutting off the rear echelons of the allies and forming the pocket. Basically alot went right for the egrmans in this case and a lot went wrong for the allies creating the historical upset.

 

[Carl Schwamberger]

So, the Ardennes plan would have been adopted anyway and the Mechelen Incident wasn't much of a factor in their planning?

Nothing is a certainity, but the more detail I find on the planning at OKW & Rundsteadts HQ the more the trajectory points to the Sickle cut.

That's a shame, it would be a good story, but history isn't that simple. It's interesting that the war games all suggested the offensive would fail. Was the big mistake then that the Allies made running into Belgium?

There was one map exercise in March where the French commander altered how the Allies we're played. A Lt Col in the Enemy Forces West section of the Intel staff decided the French would react slower than typically done in the map exercises. He delayed Allied actions by a extra 24 to 48 hours. That game went better for the attack than in the other exercises. Witnesses dismissed this as unrealistic & the French could not be so stupid.

However...

When you pick through the French actions you find exactly that going on at critical points. ie: it was clear by the evening of 11 May there was a huge enemy armored force advancing through the Ardennes, but there was a lot of indecisive waffling over deploying the several armored or mechanized corps to reinforce the 2d & 9th armies. The XX Corps was not given a warning order until the evening of the 12th & it's orders to move to Sedan did not take effect until the morning of the 13th May. That delay guaranteed the XX Corps missed the critical moment when Guderians corps broke the French defense on the 13th.


There are other cases where the decisions by the local French commanders were simply bad, but in general the senior leaders were a day or two behind events.