History Learner
Banned
How would D Day fail in summer of 44?
The only thing I can see would be a catastrophic change in the weather, but the forecasting tech of the day would have a high chance of predicting this and postponing.
The decision to go forward was pretty last second and based primarily, IIRC, on data collected by a Destroyer out in the Atlantic; just a few weeks later one of the largest Channel Storms in history hit without warning to the Allies. Incidentally, this was the hours/day following the next likely invasion window in the 18th, had the weather or perception of the weather been sufficient to prevent the June 6th window. The storm shut down resupply, air and naval support and further reinforcements for several days, which would've been a death blow for troops still establishing beachheads in Normandy.
Say D-Day fails and the WAllies need to re-group and try again. However, they launch operation Anvil on schedule and more of their force gets projected in to France via the French riviera.
To my knowledge, Operation Dragoon was never intended to be a stand alone operation and was always meant to be in tandem with Overlord landings due to the nature; the nature of the terrain meant it's a long slog to both Germany proper and the French heartland areas, as well as the fact said slog would be through hilly and mountainous terrain that would basically make the campaign another Italy. Further, given that IOTL shipping requirements for Overlord were sufficient to significantly delay Dragoon, which was supposed to occur much closer to the timing of the Normandy landings. A failed invasion likely implies high shipping losses as well as the need to begin stocking back up for another attempt which, when combined with a desire to avoid another Italy (Especially after a high casualty loss in Normandy), would can the operation.
As for what I expect to happen thereafter, me and Obssessed Nuker sparred on this recently, and my personal opinion is that nothing in so far as borders are changed Post-War. You just get the war lasting into the fall of 1945 in the ETO with a lot more dead.
By the time the Allies have recovered enough shipping and got new divisions into England for another attempt, it'll be too late in the year to try again and the next invasion window thus becomes April of 1945. The retention of Western European industry as well as the strategic buffer it provides means that the Western Allies face much greater difficult in waging the Air War of 1944-1945, in that tactical air commands don't have French and Belgian airfields to use and that FLAK has a much higher area to work with. That last is important, as new methods of AA defenses and new technologies, most particularly the dual fuse rounds coupled with the direct fire method, had reduced shell expenditures to achieve a shoot-down from around 13,000 rounds to somewhere around 1,500. Efforts to deploy the Egerland Radar system were also underway in 1945 IOTL and here might see greater success, given the greater strategic breathing provided to the Germans. The Swedes will also, given the lack of a two front war against the Germans, likely continue supplying the Germans with iron ore instead of shutting down shipments like they historically did.
As for the general situation of the East, this was a particular contention between myself and Obssessed. In my personal opinion, the situation was ripe for a major Soviet disaster in the event of a failed D-Day. IOTL, despite the horrid state of Army Group Center after Bagration, Hossbach still managed to perform some excellent counter-attacks on the Soviets. It's easy to see why in my assessment, as Soviet rifle divisions were averaging 60-85% understrength, were exhausted after months of combat, and were logistically overstretched. To this, by the start of August, the Germans will have nearly 10 Panzer and Panzer-Grenadier divisions freed up in the West with the clear realization that the main Allied effort in the West for the year has been defeated.
Now, my personal belief is that the introduction of a fresh Panzer Army would, given the situation of the Soviet forces, open them up to a major defeat if not near annihilation of Rokossovky's 1st Belorussian Front, given it's exposed position as the furthest forward element of the Soviets as well as the exhausted nature of the Soviets at this time. Obsessed strenuously disagreed with me on this, although he did make the concession it's possible the front could end up along the San/Bug instead of the Vistula as per OTL. To allow sleeping dogs to lie, we'll go with this compromise position. We'll also, for now, focus on the North European Front.
Now, operating from the position the the Soviets are stalled out on the San/Bug, this has great strategic consequences for 1945. IOTL, the Vistula-Oder offensive was supposed to start on January 22, but this was moved forward due in part to Western Allied pressure in the face of the Bulge Offensive. Here, it probably starts on the 22nd. Further, without the various disasters and the late prioritization placed on the Western Front in the form of the aforementioned offensive, the Germans have potent armored forces with which they can reinforce the Alt-"Army Group Bug" as well as Luftwaffe forces not destroyed in air offensives as they were IOTL January of 1945. As well, the Soviets will have been deprived of a major advantage they had IOTL in terms of crossing the Vistula, in that they had established bridgeheads across it prior to the main combat crossing, allowing them to stockpile logistics across the river and then launch the attacks from these sites. Here in this ATL, they will have to do a major combat crossing of the river, if not doing the same for the San/Bug, as the Germans could potentially eliminate bridgeheads over the river(s) prior to January. If Hitler can be convinced to do a better defensive planning, that's all the better for the Germans as well.
So, with this all said, what happens? Well, IOTL the Vistula-Oder covered the distance between the two rivers in about a month and then spent two months clearing out large German remnants in their flanks and rears while building back up their logistics network. Here, with a much larger German force facing them further to the East in better defenses, I don't think it's a stretch to say the operation could last two months, say from January 22 to March 2. A quick glance at Wikipedia says the Germans had 450,000 men to oppose the Soviet thrust IOTL and adding the forces used in the West would double the defenders in the ATL, as about 500,000 took part in the Bulge; I think it's sane to say a doubling of the troops opposing them can thus double the time it takes the Soviets to achieve victory. Aiding the defenders would also be the weather as another reason the Soviets brought forward the offensive was due to concerns of an upcoming thaw, which could hamper their advance if they're still facing strong opposition east of the Vistula.
So, we're saying the offensive takes two months longer, but it's also starting to the East of where it did IOTL. If it covers the same general distance as the IOTL offensive did, it probably collapses somewhere near the Vistula after taking Warsaw. The Soviets then spend some months eliminating surviving German forces at their flanks, most prominently in East Prussia, as well as forces cut off in their rear while building back their logistics. Given likely higher losses, more ammo expenditures, and the fact they had to cross two major rivers, I think it's justifiable to say instead of nearly ten weeks (February 2-April 16) as per OTL, it's 14 weeks in this ATL. So, to recap:
January 22-March 2: San/Bug to ~Vistula/Warsaw.
March 2-June 8: Clearing flanks, rebuilding logistics.
After June 8: Vistula-Oder offensive
By June I think the Germans will be in a state similar to what they were in January of 1945, and so the Soviets advance from the ~Vistula to the Oder at the rate they did historically, in about a month so that by the start of July they are on the Oder. Again, they'll need to pause and clear out Germans in their flanks (Breslau, Kustrin, Operation Solstice, etc IOTL) and rebuild their logistics, so it could be 10 weeks as per OTL, but we'll say six weeks since by July of 1945 I'd expect economic issues would be affecting the Germans badly. So, instead of doing August Storm against the Japanese as they did historically, in this ATL they're doing a major offensive against Berlin by about Mid-August. There after and concurrent, they could be overrunning the same places they did historically.
Switching gears back to the West, if you'll recall earlier I stated the next invasion window is probably April of 1945. I expect this to occur relatively easily, as by April the Ost units IOTL in use in Normandy will probably be even happier to surrender than they were IOTL and even many Germans will see the writing on the wall given the Soviet advances in Poland. More importantly, tactical and strategic air will have had long since established such a dominance over Western Europe, counter-attacks will have long since become impossible and logistical lines likely at their breaking point. I can the Western Allies landing and, with the lack of troops, logistical lines in shambles and poor morale, the Germans in France rapidly collapsing and being unable to offer serious resistance; there will be no holdups in the hedgerows nor any Mortain offensives in this ATL. IOTL, the Allies landed at the start of June and by the end of August had secured Paris and were beginning to move into Belgium; given the state of the Wehrmacht opposition they'd face in this ATL, you could halve this advance time in half I think justifiably into a month instead of the two as historically.
So, presuming a landing in Mid-April, by Mid-May they'd have largely overrun France and be in the process of doing the same in Belgium. They probably still take Antwerp intact but also will in a position to more rapidly bring it online, given the weaker abilities of the Germans to contest the sea lanes leading into it. We'll say by June the port is operational and this grants the logistical capability to secure Holland be establishing bridgeheads over the Rhine by sometime in July. Thereafter, for any remaining time in July and into August, the Western Allies will be rapidly advancing across Germany as they did over the course of March-April of 1945. They then meet the Soviets at the Elbe sometime around late August. Mop ups continue into September, but at this point the war is largely over. Luckily for the Germans, it ends before nuclear weapons can be used against them. Unluckily for the Japanese, the continue dedication of forces in the ETO means for sure no invasion of the Home Islands, meaning the Allies probably go for the starvation strategy advocated by the USAAF and USN as well as delay the atomic bombings until September; they'll make up for that by doing more of them at once instead of just two as they did IOTL.