WI No Reinberger incident: No Sickle-Cut?

[Finbarr the Fair]

I've been re-reading Blitzkrieg, by Lloyd Clark, to help me follow AlanpCameron's excellent TL on British tanks and the Battle of France and beyond.

One thing struck me as a potential POD for other TLs and a "What IF" question for the forum

Hitler had ordered the Offensive in the West to start on 12 January, on the prediction of a 2 week spell of fine weather. But, on 10 January a careless/reckless/stupid* Major on the airborne forces general staff caught a plane for an unauthorised flight carrying documents outlining much of the campaign plan. This made an emergency landing in Belgium, spilling the beans as it were to the Allies. The offensive was postponed and in the time between January and its launch on 10 May, Mansteins ambitious/audacious/bold* plan for the main assault to go though the Ardennes had been accepted. The Allies were wrong-footed and the rest, so to speak, is OTL History.

BUT - what if the hapless Major Reinberger had not taken his flight or even had the plane not been forced to land in Belgium? How would the German assault have fared?

Both sides would have been weaker in January than May while the short days and probable bad weather by late January would militate against a sustained rapid German advance. Gamelin's Plan D had I think been "approved" but not turned into a full Operational Plan, with movement instructions etc. How ready was the Belgian army?

My guess is that the initial German attacks would mostly be stopped on the Albert Canal but any bridgehead could be exploited then or later to throw the Allies into disarray. The fundamental sluggishness of the French C3I process means it would have difficulty reacting in a timely fashion. But, could the Germans keep up attacks as Monty and Bradley did in Normandy until something cracked? Or would the Allies greater resources enable them to stop the Germans definitively and maintain a defensive line somewhere?

Anyone else got an opinion? Or know of a TL that covers this scenario? Or even an old war-game.

* Delete as appropriate

 

[Garrison]

I think postponement and Sickle Cut are still fairly likely, but without the Reinberger incident my guess is that the French won't reinforce the Dyle Plan as they did OTL and there will still be a powerful reserve in a position to block the Germans at Sedan. If the fighting bogs down the Germans are in serious trouble.

 

[RedSword12]

Hitler was dissatisfied with Franz Halder's plan which would essentially be a reenactment of World War I. Manstein's plan would probably still be adopted, and probably would still be successful. French plans for war against Germany revolved around sending massive numbers of troops into Belgium to man the natural river line defenses, and I don't think the Reinberger incident was the inciting factor behind the French following the plan they'd been intending to use, throughout the interwar period. It probably merely reassured them.

 

[Bougnas]

If there is a last minute change of mind in Germany and the attack is postponed (which likely allows Manstein's plan to eventually prevail), not much will change. Entente developments were still mostly independent of the incident and while it would remove an alert in January and possibly lead to a slightly weaker Dyle plan to keep more reserves to prepare for anything, I think that the French deployment would not have changed much as French intelligence had a pretty good idea of when the Germans were going to attack and knew at least that the Low Countries were targetted.

If Hitler lets the offensive start on the 12th of January however...

For a start while the "Holland hypothesis" was discussed as early as November 1939, it was only really in March 1940 that the Breda part of the plan was actually enacted. So by all accounts the French 7th Army tasked to do this would have remained in reserve, and since the Ardennes are not attacked that means that it will be eventually sent to Belgium. I've not been able to verify if the Escaut or Dyle plan was favored in January, both were considered with the Dyle plan being possibly not quite ready, but the final decision was dependent on whether the Belgians ask for help soon enough. And going by OTL they would have screamed for help soon enough, so it's probably Dyle.

What happens is dependent on how the forces compared at this point and the personal decisions made, but I personally don't think the Germans will be able to replicate the swift encirclement of Anglo-French forces the way they did OTL. However if it's Dyle then the French are still fighting encounter battles, that they can win but with substantial losses. If it's Escaut then the Belgians will be alone and take a huge amount of damage but the French will be in better prepared positions and with better logistics so they will do better.

I don't think that the Germans can win in a matter of weeks, but:

-best case scenario the Entente actually stops the Germans in Belgium and then it's just a matter of waiting until enough war material is produced, but the Germans can still have a shot at an offensive in the Spring/Summer.

-middle case scenario the Entente forces suffer heavy losses and retreat but thanks to reserves can still stop the Germans somewhere in France, but most likely still in a better position than in 1914.

- worst case scenario (but dubious), the Germans manage to inflict so much damage and break through in so many areas that the Entente retreats too far to stabilize the front, but the battle likely remains substantially longer than OTL.

However, I think that timing would have been in the Entente's favor here, as the Germans have a limited window of good weather. The Luftwaffe will probably be less of a factor, although it's still the ground forces that matter.