Operation Fortitude fails.

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Geoffrey Cooke
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Operation Fortitude fails.

Post by Geoffrey Cooke » 10 Feb 2023 21:22

What if operation fortitude had been compromised and the Germans were obliged to put more emphasis building up forces in Normandy than Pas de Calais for the expected invasion?

What the Allies have gone ahead with Normandy anyways? Brittany instead? Would they have gritted their teeth and gone straight for Pas de Calais: a victory there meaning a more direct slashing distance from the Reich’s jugular? Maybe even an earlier Dragoon/Anvil operation instead?

Personally I’d be interested if the Allies had taken the Mediterranean route: the weakest defended of the areas, and unlikely to attract strong German forces for some time due to the threat of a cross channel invasion.
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T. A. Gardner
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Re: Operation Fortitude fails.

Post by T. A. Gardner » 10 Feb 2023 22:52

Let's say it does for whatever reason. Several things are likely to happen.

1. The Allies will still have a near certain idea where something like 85 to 90%+ of German units in France are. They will still have an equally good idea where and what German fortifications are.

2. The Germans still won't have much of a clue where the Allies might land. They may still assume the Calais area, or possibly somewhere else.

3. The Allies could plan their landing(s) for any number of locations in response to the German changes in deployment.

4. The Allies could, and likely would, introduce other deception plans that result in more or less the same original deployment and outcome.

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Re: Operation Fortitude fails.

Post by Kingfish » 10 Feb 2023 23:10

Geoffrey Cooke wrote:
10 Feb 2023 21:22
What if operation fortitude had been compromised and the Germans were obliged to put more emphasis building up forces in Normandy than Pas de Calais for the expected invasion?
Compromised when?
D-2 months is a lot different than D-2 days.

Does your WI assume the allied are aware it is compromised?
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Re: Operation Fortitude fails.

Post by Geoffrey Cooke » 11 Feb 2023 00:08

T. A. Gardner wrote:
10 Feb 2023 22:52
Let's say it does for whatever reason. Several things are likely to happen.

1. The Allies will still have a near certain idea where something like 85 to 90%+ of German units in France are. They will still have an equally good idea where and what German fortifications are.

2. The Germans still won't have much of a clue where the Allies might land. They may still assume the Calais area, or possibly somewhere else.

3. The Allies could plan their landing(s) for any number of locations in response to the German changes in deployment.

4. The Allies could, and likely would, introduce other deception plans that result in more or less the same original deployment and outcome.
Yes, I agree with points 1-3, but where would they likely land if fortitude didn’t work (AKA Normandy was better defended) is what I’m mainly interested in.

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Re: Operation Fortitude fails.

Post by Geoffrey Cooke » 11 Feb 2023 00:20

Kingfish wrote:
10 Feb 2023 23:10
Geoffrey Cooke wrote:
10 Feb 2023 21:22
What if operation fortitude had been compromised and the Germans were obliged to put more emphasis building up forces in Normandy than Pas de Calais for the expected invasion?
Compromised when?
D-2 months is a lot different than D-2 days.

Does your WI assume the allied are aware it is compromised?
Enough time ahead for German deployment to be seriously effected. I imagine the Allies would intuit from German deployment that it was compromised, or at least not working, whether they truly “knew” it or not. What I’m wondering specifically is: would it have deterred a landing in the Normandy area and moved it to another place where the Germans couldn’t afford to heavily defend regardless of the success or failure of Allied deception, like the French Atlantic coast or the Mediterranean coastal area thanks to the cross channel threat, at the cost to the Allies that it was a less convenient invasion area?

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Re: Operation Fortitude fails.

Post by Carl Schwamberger » 11 Feb 2023 02:10

Yes, I agree with points 1-3, but where would they likely land if fortitude didn’t work (AKA Normandy was better defended) is what I’m mainly interested in.
Lets take a look at the historical record. Normandy was better defended in late February than when the initial plan of 21 Army Group was first briefed to SHEAF & the other leaders. It was better defended in early April than in late February, and it was yet better defended at the end of May when the units began preparing for the 5 June target date. Each time the Allied intelligence services detected a improvement in the defense they sought a way to strengthen the attack.

The first significant change was in January when Rommel started construction of the beach defenses Hitler had just authorized. Until then Rundsteadts strategy had been to leave only a outpost line on the beaches (the ports were already fortified) and defeat the invasion inland in a large mobile armored battle. The landing plans made by COSSAC in 1943, and then up dated by 21 Army Group in December/ January were based on the late 1943 beach defenses, which were not fortifications. Studying the construction caused the Allied planning staffs to increase the naval and air fire support for the initial assault, and increase engineer battalions in the first waves. The assault infantry were trained to attack fortified beaches vs simple trenches and sandbags.

The landing plan its self was adjusted during February-April to account for German reinforcements to the 7th Army area of Normandy. So was the follow up plan for advancing inland to capture the Normandy region west of the Seine river and Cherbourg. This adjustment included allocation of naval fire support and the bombing plan for before and after the beach assault. If you read through Dolittles biography or Bradleys, or the history of the US 9th Air Force you can find a few remarks about these adjustments.

What about last minute adjustments? One example is the transfer of the German 352 Infantry Division from the west coast of the Cotientin near Lesse to the east side between Bayuex & Carentan. Allied intelligence did not detect this movement until June and Bradley did not receive the memo until about 4th June. At that point there was very little of practical value he could do, & when the Corps Commander received the information there was nothing he could do that would not disrupt the assault and landing. Attempting last minute adjustments would create further confusion and disorder. At that point they could cancel the attack entirely, or go ahead and hope. As it was they choose to attack anyway.

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Re: Operation Fortitude fails.

Post by Carl Schwamberger » 11 Feb 2023 02:29

To digress:

Operation FORTITUDE was not a isolated one off operation. From 1941 the Brits had been conductging a organized series of mutually supporting deception operations. Holt in his 800+ page book 'The Deceivers' catalogs and analysises these Brit and later Allied operations. One point Holt touches on that most other historians do not is that the Deception Committee masterminding all these operations were using the ULTRA system to tailor the operations to German thinking. They were searching the decrypts of the radio traffic in and out of OKW, Rundsteadts HQ, Kesselrings HQ, ect... for clues as to what the German leaders favored or feared about Allied actions. That is the deception ops were designed to reinforce certain fears about the Allied intent. This analysis of the radio traffic & other sources created a feed back loop which the operation managers used to adjust their activity to fit German prejudices.

So, could the Germans have not been fooled? The short answer is yes. The Italians seem to have been less vulnerable to the deception ops. In comparison too the Germans the Japanese seem almost immune. They were surprised a lot less often and better anticipated the Allied operations across the Pacific and Asia. So Allied deceptions ops were not guaranteed. To a extent it was Hitlers poor strategic and operational sense that helped the British Deception Committee succeed.

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Re: Operation Fortitude fails.

Post by T. A. Gardner » 11 Feb 2023 03:20

Geoffrey Cooke wrote:
11 Feb 2023 00:08
T. A. Gardner wrote:
10 Feb 2023 22:52
Let's say it does for whatever reason. Several things are likely to happen.

1. The Allies will still have a near certain idea where something like 85 to 90%+ of German units in France are. They will still have an equally good idea where and what German fortifications are.

2. The Germans still won't have much of a clue where the Allies might land. They may still assume the Calais area, or possibly somewhere else.

3. The Allies could plan their landing(s) for any number of locations in response to the German changes in deployment.

4. The Allies could, and likely would, introduce other deception plans that result in more or less the same original deployment and outcome.
Yes, I agree with points 1-3, but where would they likely land if fortitude didn’t work (AKA Normandy was better defended) is what I’m mainly interested in.
Then the Allies potentially go elsewhere. They have complete initiative on where they'll land. They have absolute control of the seas off France so the Germans can't stop them before they show up. The Allies also have far, far better intelligence on what the Germans are doing than the reverse. The Germans have no spies in Britain--unless you count the ones the British turned that are feeding false information to the Germans.

The Germans can barely manage the occasional overflight of Britain for photo reconnaissance.

If the Allies thought Normandy was too tough a spot to land, they go elsewhere.

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Re: Operation Fortitude fails.

Post by Carl Schwamberger » 11 Feb 2023 10:40

If the Allies thought Normandy was too tough a spot to land, they go elsewhere.

Have this occur far enough ahead, then Eisenhower does not cancel Operation ANVIL. That operation originally planned by COSSAC with a April target date was intended to draw off the reserves of OB West. Ike was more committed to maximizing the assault and immediate follow up for Operation Neptune, so in March canceled the weakening ANVIL op. The ground and air forces intended for Op ANVIL remained in place in the Mediterranean, so its a matter of shifting the necessary amphibious lift back to the western MTO. Aside from drawing off the defenders reserves from the north it gives the Allies a generous port capacity months ahead of the capture of Cherbourg OTL. I've gamed this ANVIL variant numerous times and found there's some distinct advantages on the game board. Where the Allied player has the option of executing either ANVIL or NEPTUNE first the defense has to thin out the coastal defense too much. Cant cover all the likely landing sites.

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Re: Operation Fortitude fails.

Post by T. A. Gardner » 11 Feb 2023 18:24

Or Anvil coupled with a smaller D-Day at Quiberon Bay or further south along the French Atlantic coast. The two push to link up and form a solid front in Southern France. The defenses are weak enough they would easily be overcome and Allied destruction of the rail and road net would still occur meaning the German response would be slow and piecemeal.

The Allies still get ashore, stay ashore, and build up faster than the Germans can.

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Re: Operation Fortitude fails.

Post by Carl Schwamberger » 25 Feb 2023 21:39

On the game board the southern options are ok. Further from the Ruhr or Berlin, and less robust rail connections that further north. Bourdeux is the only mega port south of Brest on the Atlantic coast. But as you say its a wide front and inherently weaker defense.

The game boards usually reflect that the Allied tactical air forces cant support that far south in terms of preiavasion preparation, or in the assault phase. The A20s, Blenheims, Typhoons, B26, ect.. cant reach much south of St Malo or maybe Rennes from southern Britain. Conversely the Rivera is in easy range of the 3000+ combat aircraft the Allies surged into Sardinia & Corsica in the summer of 1944.

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Re: Operation Fortitude fails.

Post by Carl Schwamberger » 18 Mar 2023 20:25

Geoffrey Cooke wrote:
10 Feb 2023 21:22
What if operation fortitude had been compromised and the Germans were obliged to put more emphasis building up forces in Normandy than Pas de Calais for the expected invasion?
Revisted this question and rewrote it slightly:


What if operation FORTTUDE had been compromised from 6th June and the Germans released forces to 7th Army in Normandy from 15th Army covering the Pas de Calais for the expected invasion?



At one of the late pre invasion briefings Eisenhower was briefed on the current expectations of Op FORTITUDE after D Day. Ike remarked that if they kept the 15th Army off his back for two weeks it would be enough.

This was drawn partially from pre invasion knowledge of Hitler & others focus on the Calais and Flanders coasts as the probable main invasion site, and the German misunderstanding that the Allies would make only one effort and not a multi site series of two or more invasions. In this the Allied deception organization planted information for OKW & Rundsteadt that led them to think any invasion would only be a diversion from a larger effort the same summer. Allied intelligence & Ike understood this German PoV.

If the Germans fail to follow this complex ruse & release all possible reinforcements for 7th Army in Normandy Ikes hope is unfulfilled. At this point my only analysis is drawn from the game board. That tells me the Allied Op OVERLORD is in trouble, but not automatically defeated. Two problems hinder the German effort. First is the Allied interdiction of the German supply transport is still in effect. OTL Rundsteadt was unable to deliver any significant amount of supply to Normandy. The fight with the invasion force depended mostly on existing 7th Army depots, which were substantial, but still not adequate, they were near exhausted in late July. As little as 10% of requirements arrived from Germany in June and July. So, rushing reinforcements from 15th Army, or 1st Army, or the Netherlands puts more divisions on the ground, but proportionately increases the supply problem.

A second problem is the Bocage worked both ways. The Germans found excellent defensive opportunities in it. So did the US Army. The Bocage, the streams and marshlands of the Cotientin, and the automotive choke point of Caen & several smaller towns constrict the ability of the Germans to mass a extra 50%, 75%, or 100% of combat formations. The usual result on the game board is a longer lasting stalemate. Far into August or even September. Before Rommels army group breaks and Rundsteadts OB West is in trouble.

Of course there is a more than trivial chance the OVERLORD operation is defeated. The Allied armies trapped into winter, or driven off entirely. Bad dice rolls or player decisions & skill can create this situation, and the reverse.

Anyway, if the entire 15th Army reserves are released from 6th June then the overall effect may be Montys 21st Army Group is confined to Normandy 1-3 extra months.

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