WW2 Air war in Europe with a defeated USSR?

[TheMarcksPlan]

...

[KDF33]

More Hamburgs did occur.

I believe TMP's argument is that, in the face of far stronger Luftwaffe opposition, it is a fair question to ask if the Allies would have had comparable success at strategic bombing than historically, or even if the CBO would have remained a viable option. Not that Hamburg was a singular success for the actual CBO.

[daveshoup2MD]

More Hamburgs did occur.

I believe TMP's argument is that, in the face of far stronger Luftwaffe opposition, it is a fair question to ask if the Allies would have had comparable success at strategic bombing than historically, or even if the CBO would have remained a viable option. Not that Hamburg was a singular success for the actual CBO.

Not much of a success for Germany, was it? 30-40,000 dead, 150,000 or so injured or rendered homeless; much of the city destroyed; not certain how many victories like that even Nazi Germany could have dealt with - so much winning.

Well, even if the Soviets surrender or sign an armistice or whatever (since neither Politician nor TMP have suggested what is supposed to happen, and when, exactly), Hamburg was in July, 1943, which suggests the LW isn't going to be any stronger than it was historically at that point in the West, over Germany, or the MTO. Stalingrad, of course, was in 1942-43, which sort of suggests the Soviet's resiliency.

There's also the minor point that by July, 1943, the Allies were already in Italy, which sort of suggests that Foggia is not that far away; all in all, the time frames also suggest that even the eastern front went quiet at some point in 1942-43, the time necessary for redeployments, reequipment, etc is going to slow down any immediate change in in the relative strengths of the air forces. There's also the minor point that Hamburg was turned into an inferno by the RAF night attacks (the USAAF day attacks helped keep the German situation a bad one, of course), and I'm not aware the LW had huge numbers of night fighters in the East in 1942.

To get to the point where a Soviet collapse actually frees up enough Axis strength to make a difference in the theaters where the Allies engaged in 1942-43 probably requires a collapse in 1941, which is pretty close to unimaginable.

So is a Soviet collapse in 1942 or 1943, all else being equal, but that's the historical reality, and this is "alternative history" not historical alternatives.

So even if the USSR backs out in 1942-43, the Allies are in deep in the Med, which opens up the air war against the Axis from two directions; it also leaves the Allies very well placed for some very special missions in 1945 - although Ploesti (much less Baku) were well within reach from Allied air bases in SW Asia as early as 1942.

[KDF33]

Not much of a success for Germany, was it? 30-40,000 dead, 150,000 or so injured or rendered homeless; much of the city destroyed; not certain how many victories like that even Nazi Germany could have dealt with - so much winning.

Are you addressing me or someone else here? I'm at a loss to figure out who you think considers Gomorrah a German victory.

Well, even if the Soviets surrender or sign an armistice or whatever (since neither Politician nor TMP have suggested what is supposed to happen, and when, exactly)

TMP has fleshed out scenarios in multiple threads. See here or here, for instance. I don't think Politician is active anymore.

Hamburg was in July, 1943, which suggests the LW isn't going to be any stronger than it was historically at that point in the West, over Germany, or the MTO. Stalingrad, of course, was in 1942-43, which sort of suggests the Soviet's resiliency.

I'm not clear on what the argument is here.

There's also the minor point that by July, 1943, the Allies were already in Italy, which sort of suggests that Foggia is not that far away; all in all, the time frames also suggest that even the eastern front went quiet at some point in 1942-43, the time necessary for redeployments, reequipment, etc is going to slow down any immediate change in in the relative strengths of the air forces. There's also the minor point that Hamburg was turned into an inferno by the RAF night attacks (the USAAF day attacks helped keep the German situation a bad one, of course), and I'm not aware the LW had huge numbers of night fighters in the East in 1942.

I'm not sure why you focus so much on July 1943. You do realize you were the first to mention Hamburg in this thread, not TMP? TMP never based his argument around that timeframe.

To get to the point where a Soviet collapse actually frees up enough Axis strength to make a difference in the theaters where the Allies engaged in 1942-43 probably requires a collapse in 1941, which is pretty close to unimaginable.

On that specific point, my personal view is that a Soviet collapse in 1942-43 would completely change the balance of force, but IIRC TMP's general argument is based on an earlier Soviet collapse, in the 1941-42 timeframe.

So is a Soviet collapse in 1942 or 1943, all else being equal, but that's the historical reality, and this is "alternative history" not historical alternatives.

I strongly disagree on this. I have started to flesh out my views here.

So even if the USSR backs out in 1942-43, the Allies are in deep in the Med, which opens up the air war against the Axis from two directions; it also leaves the Allies very well placed for some very special missions in 1945 - although Ploesti (much less Baku) were well within reach from Allied air bases in SW Asia as early as 1942.

My understanding of TMP's argument (as well as my own reading of the likely situation in the event of Soviet collapse) is that the trouble for the Allies has little to do with geography, and everything to do with a vastly stronger Luftwaffe and German war economy.

But even then, your assumption that the Allies are "deep in the Med" is based on your own assumptions about the timeline, not on TMP's argument.

[TheMarcksPlan]

My understanding of TMP's argument (as well as my own reading of the likely situation in the event of Soviet collapse) is that the trouble for the Allies has little to do with geography, and everything to do with a vastly stronger Luftwaffe and German war economy.

But even then, your assumption that the Allies are "deep in the Med" is based on your own assumptions about the timeline, not on TMP's argument.

Yes, my post-SU ATL is based primarily on a much stronger LW (and KM) due to much stronger German economics. I've been working from Soviet defeat/collapse around September '42, once Ostheer occupies the central Urals.

Incidentally but importantly, the Allies do have a geographical problem in that America is far from Germany. This is "duh" but is underrated by most analysts. The distance factor imposed enormous costs on the US not borne by Germany. Shipping of course but it also aggravated the incredible preponderance of service troops versus combat troops for the U.S. It's a large part of why a >5mil-man army had only 90 divisions.

If I ever get around to finishing my broader ATL, that division slice problem will loom large: America will need many more than 90 divisions if the ATL involves them not making peace before 1945. Those divisions will draw heavily on American labor, which was, of course, the world's most productive in factories but quite inefficient when translated into combat power.

Thank you for responding to to dave, allowing me to delete an earlier response that may not have passed moderator muster.

[daveshoup2MD]

Not much of a success for Germany, was it? 30-40,000 dead, 150,000 or so injured or rendered homeless; much of the city destroyed; not certain how many victories like that even Nazi Germany could have dealt with - so much winning.

Are you addressing me or someone else here? I'm at a loss to figure out who you think considers Gomorrah a German victory.

Well, even if the Soviets surrender or sign an armistice or whatever (since neither Politician nor TMP have suggested what is supposed to happen, and when, exactly)

TMP has fleshed out scenarios in multiple threads. See here or here, for instance. I don't think Politician is active anymore.

Hamburg was in July, 1943, which suggests the LW isn't going to be any stronger than it was historically at that point in the West, over Germany, or the MTO. Stalingrad, of course, was in 1942-43, which sort of suggests the Soviet's resiliency.

I'm not clear on what the argument is here.

There's also the minor point that by July, 1943, the Allies were already in Italy, which sort of suggests that Foggia is not that far away; all in all, the time frames also suggest that even the eastern front went quiet at some point in 1942-43, the time necessary for redeployments, reequipment, etc is going to slow down any immediate change in in the relative strengths of the air forces. There's also the minor point that Hamburg was turned into an inferno by the RAF night attacks (the USAAF day attacks helped keep the German situation a bad one, of course), and I'm not aware the LW had huge numbers of night fighters in the East in 1942.

I'm not sure why you focus so much on July 1943. You do realize you were the first to mention Hamburg in this thread, not TMP? TMP never based his argument around that timeframe.

To get to the point where a Soviet collapse actually frees up enough Axis strength to make a difference in the theaters where the Allies engaged in 1942-43 probably requires a collapse in 1941, which is pretty close to unimaginable.

On that specific point, my personal view is that a Soviet collapse in 1942-43 would completely change the balance of force, but IIRC TMP's general argument is based on an earlier Soviet collapse, in the 1941-42 timeframe.

So is a Soviet collapse in 1942 or 1943, all else being equal, but that's the historical reality, and this is "alternative history" not historical alternatives.

I strongly disagree on this. I have started to flesh out my views here.

So even if the USSR backs out in 1942-43, the Allies are in deep in the Med, which opens up the air war against the Axis from two directions; it also leaves the Allies very well placed for some very special missions in 1945 - although Ploesti (much less Baku) were well within reach from Allied air bases in SW Asia as early as 1942.

My understanding of TMP's argument (as well as my own reading of the likely situation in the event of Soviet collapse) is that the trouble for the Allies has little to do with geography, and everything to do with a vastly stronger Luftwaffe and German war economy.

But even then, your assumption that the Allies are "deep in the Med" is based on your own assumptions about the timeline, not on TMP's argument.

You stated "Not that Hamburg was a singular success for the actual CBO," which sort of implies it was a success for "somebody" other than the Allies.

TMP's argument is based on a Soviet collapse in September, 1942, with the Axis as far east as the Urals, which is - quite the handwave. Adding in the Caucausus and Transcaucasia (which is where the oil is), much less Central Asia, makes it even more of one.

But even with that, the Germans are -apparently - occupying most of European Russia, with all those Russians to round up; takes some effort just to do that. How many divisions did the Germans leave in occupied Russian territory in 1918, again? And that occupied zone was minuscule compared to what TMP is suggesting below...

Then they have to decide what to do next, where to deploy or redeploy any assets that are freed up, actually move them and sustain, them, etc.

Meanwhile, the Allies were already in a position to land in French North Africa, and are already in control of Egypt, the Levant, Cyprus, (all pretty deep in the Med) and points east, all the way to Iran, along with the Soviets and the Poles; which makes for an interesting question - if the Soviets follow the same path as the Poles, there's a pretty good sized "Free Russian Army" available to keep fighting, and given the topography of Anatolia and the Elborz Range, it's not exactly "good tank country."

Anyway, so there's something of a stalemate, with the Allies hitting the Axis where they ain't, thoughout - if everybody keeps fighting, which given the Axis track record, why would they stop - until 1945 or so (maybe even earlier, given the strategic re-prioritization), several places of great importance to the Axis pretty much - and suddenly - cease to exist.

Which is when the air war gets interesting.

[TheMarcksPlan]

TMP's argument is based on a Soviet collapse in September, 1942, with the Axis as far east as the Urals, which is - quite the handwave.

No, Dave, the handwave is you refusing to address substantively the argument, handwaving any suggestion that the SU might have been defeated by then.

To repeat, I invite your substantive discussion of the Eastern Front issues in an appropriate thread.

Meanwhile, the Allies were already in a position to land in French North Africa, and are already in control of Egypt, the Levant, Cyprus, (all pretty deep in the Med) and points east, all the way to Iran

Nope. But it involves a substantive discussion that you've so far shown yourself unwilling to undertake.

[daveshoup2MD]

[/quote]America will need many more than 90 divisions if the ATL involves them not making peace before 1945.[/quote]

To do what, exactly? (And juts to stress the point, 96, actually, including the USMC; more combat divisions then the Canadians deployed overseas should count for something ... then one can start assembling division equivalents from various separate brigades, regiments, groups, etc., as well as considering the impact of active conscription for overseas service in the dominions, mobilization of additional "colonial" forces in Africa and India, mobilization of additional manpower from Latin America, organization and equipment of exile Russian forces, etc.)

Even in Q4 of 1942, the allies already controlled Greenland, Iceland, and the UK, and could have occupied the Portuguese and Spanish Atlantic islands whenever necessary; the Allies landed in French North Africa in the same year and took control of all but Tunisia in the space of a week, absent the Spanish and Portuguese islands. The Allies also controlled Egypt, the Levant, Cyprus, etc.

Given the record of the Axis in expeditionary warfare in Africa in 1940-43, and the state of the Italian Navy and Merchant Marine by the end of 1942, rather difficult for any substantive redeployment of Axis combat power, certainly not enough to overcome the very substantial forces the Allies already have and can deploy into both areas. Stalemate seems likely.

Beyond that, there's still a hot war for a couple of years, while the Axis are trying to create an autarky while simultaneously slaughtering the Slavs, and sometime in 1944-45, Baku or Ploesti or Berlin or the Ruhr or all of the above are suddenly very different places then they were the day before.

That would be an interesting air war. Once the Axis NCA is gone or disrupted, presumably a series of Hamburgs or Dresden start occurring thanks to basic chemistry, as opposed to advanced physics.

[daveshoup2MD]

TMP's argument is based on a Soviet collapse in September, 1942, with the Axis as far east as the Urals, which is - quite the handwave.

No, Dave, the handwave is you refusing to address substantively the argument, handwaving any suggestion that the SU might have been defeated by then.

To repeat, I invite your substantive discussion of the Eastern Front issues in an appropriate thread.

Meanwhile, the Allies were already in a position to land in French North Africa, and are already in control of Egypt, the Levant, Cyprus, (all pretty deep in the Med) and points east, all the way to Iran

Nope. But it involves a substantive discussion that you've so far shown yourself unwilling to undertake.

These are the same Axis who were throwing the Italian, Romanian, and Hungarian armies into the fray on the Eastern Front in 1942, correct?

[KDF33]

You stated "Not that Hamburg was a singular success for the actual CBO," which sort of implies it was a success for "somebody" other than the Allies.

Ah, I see. I meant that TMP's argument is not based on Hamburg being a one-off success for the Allies, but rather that a stronger Germany, especially in the air, would make more difficult / preclude further successes on the scale of Hamburg. "Singular" was meant as "unique", but in fairness it wasn't the best-constructed sentence.

TMP's argument is based on a Soviet collapse in September, 1942, with the Axis as far east as the Urals, which is - quite the handwave. Adding in the Caucausus and Transcaucasia (which is where the oil is), much less Central Asia, makes it even more of one.

My understanding of TMP's argument regarding the scenario of an early collapse of the USSR is that Germany goes in assuming a multi-campaign commitment, with the effort to harness the resources of occupied Europe happening as soon as the decision for Barbarossa is taken, rather than in December 1941 / January 1942.

But even with that, the Germans are -apparently - occupying most of European Russia, with all those Russians to round up; takes some effort just to do that. How many divisions did the Germans leave in occupied Russian territory in 1918, again? And that occupied zone was minuscule compared to what TMP is suggesting below...

We don't have to go back that far. The Germans occupied Soviet territories containing a pre-war population of ~80 million people in 1942. They deployed 99,500 field troops in the RKs Ostland and Ukraine in mid-1942, which contained the vast majority of the occupied population. Throw in SS/police and the Germans occupied the USSR with a few hundreds of thousands of men, most of them paramilitary rather than active troops.

Anyway, so there's something of a stalemate, with the Allies hitting the Axis where they ain't, thoughout - if everybody keeps fighting, which given the Axis track record, why would they stop - until 1945 or so (maybe even earlier, given the strategic re-prioritization), several places of great importance to the Axis pretty much - and suddenly - cease to exist.

Which is when the air war gest interesting.

This is similar to what TMP is claiming: the defeat of the USSR would lead to a conventional stalemate, one the Anglo-Americans would require nuclear weapons to break. You put the emphasis on the nuclear tie-breaker, whereas he puts it on the ability of the Germans to defend their conquests against a conventional air effort.

[KDF33]

These are the same Axis who were throwing the Italian, Romanian, and Hungarian armies into the fray on the Eastern Front in 1942, correct?

Well, Italy, Romania and Hungary were all part of the Axis, so its a bit odd to claim the "Axis" was throwing "them" in the fray. But I guess you really meant "Germany" was.

Besides, Italy, Romania and Hungary provided between them ~800,000 ground troops to the Eastern Front in the fall of 1942. That was a significant and valuable commitment to the war effort, and I don't see why their deployment is an argument against the possibility of Soviet defeat.

[TheMarcksPlan]

This is similar to what TMP is claiming: the defeat of the USSR would lead to a conventional stalemate, one the Anglo-Americans would require nuclear weapons to break

Broadly yes, but the boundaries and conditions of stalemate, in my view, should be clarified:

First - the Med. Here it's different from early 1942 because the SU - though still standing - is sufficiently weakened that Hitler can afford:

• To take Malta in early '42 using a one or two ID's diverted from Eastern Front plus the anti-shipping LW units held in Norway OTL. Historical conditions did not allow for such diversions but Hitler knew of their sense, had they been possible: He and Raeder discussed taking Malta in Spring '41, slating it for after Barbarossa.
• To dispatch at least 3 mechanized divisions to Rommel by June '42 (probably under a new CinC Afrika like Rundstedt), probably resulting in 8th Army's practical destruction around Gazala or its preemptive retreat to the Nile.

By September '42, with the Central Urals secured and the SU either impotent or Vichy'd, Hitler is already reinforcing France/Libya. Again, he and Raeder discussed the Northwest Africa's critical importance during Spring '41 and predicted the Americans - not even in the war yet - would first move there.

Then there's a probability fork in Fall '42:

Path A:
Spain and Turkey either enter the war on Axis side or invasion build-up against them commences. Spain is likely to join the Axis under (tacit but clear) threat of German invasion - as Franco seemed ready to do had Hitler taken such moves in 1940. Turkey seems likely at least to allow Axis passage (in exchange for Cyprus, Aegean islands, maybe some of Iraq and Armenia). then the entire Allied position north of the line Abadan-Suez (inclusive) is untenable. Allied shipping logistics render a strong defense in the Middle East impossible.

With Malta and Suez gone, with the Axis holding the Strait of Gibraltar, Torch is impossible and/or unwise. Most Allies can/should do is land in the Canaries and on Morocco's Atlantic coast. Mediterranean is an Axis lake.

On this probability path - IMO the most likely one - it's hard to see the Allies holding anything on the Eurasian landmass.


Path B:
Turkey and/or Spain resist the Axis. This slows things down in the Med, allowing the Allies time to do Torch and provide weak assistance to Turkey.

But Torch doesn't lead to Tunisgrad: Rommel is on the Nile, Suez, or further east. Hitler has anticipated Torch and reinforced Libya - maybe even invaded Tunisia himself already. Malta's fall and LW's reinforcement from Ostheer means secure Axis shipping - if necessary to Sfax and Tripoli rather than Tunis/Bizerte.

The danger in this probability fork is it's only a matter of time before Allied armies are stuck in land battles they can't win - in Iberia, Algeria, and/or Middle East. Unlike Path A, Path B invites Allied deployments that likely lead to disastrous Allied defeats with the capture of huge masses of soldiers. Politically, the European war probably ends there.

Finally, we should not ignore the possibility of Sealion '44/'45. As Hitler stated in Directive 32B for the post-Barbarossa period:

Preparations for the invasion of England will serve the double purpose of tying down English forces at home and of bringing about a final English collapse through a landing in England.

The post-SU stalemate would require a buildup of American/Anglo armies to guard against Sealion and to stop Axis advances across the whole Eurasian landmass. Raising these armies would significantly reduce Allied war production.

If the Allies failed so to enhance their ground forces, then the stalemate may be ended by Germany conquering England.

--------------------------------

Don't forget Japan:

Fall of SU frees Kwantung Army to defeat China and threaten India in '43. Supplying a strong CBI front is a logistical nightmare, creating a massive drain on Allied resources.

With China defeated, Japan's Manchurian/Korean industrial base can't be bombed until the Allies get to Okinawa.

---------------------------------

The stalemate eventually could take an essentially Trans-Atlantic/Pacific character, with the Axis controlling all of Eurasia.

[TheMarcksPlan]

To take Malta in early '42 using a one or two ID's diverted from Eastern Front plus the anti-shipping LW units held in Norway OTL. Historical conditions did not allow for such diversions but Hitler knew of their sense, had they been possible

From the minutes of a Fuehrer Conference with Raeder on June 17, 1942:

The Fuehrer recognizes how important it is to take Malta. However, he does not believe that this can be done while the offensive on the Eastern Front is in progress, and especially not with Italian troops. During that time the Air Force cannot spare any transportation planes.

...that Hitler didn't think HERKULES possible with Italian troops is never mentioned in secondary sources that I've seen, but it's clear from the primary sources.

In my ATL, Ostheer takes ~300k fewer permanent casualties by May '42 (RKKA soldiers encircled rather than attritted normally) and SU/RKKA is ~40% weaker in May '42 than OTL (loss of more territory and soldiers). Hitler thereby has additional soldiers and knows he can spare them for the Med.

Merely doubling Rommel's force in Spring '42 (3 divisions) means at least that Alexandria can't be held. How far Rommel can go afterwards depends on whether he's destroyed 8th Army before reaching Alexandria (i.e. whether it fights 6 German divs in Libya) and on logistics. In any event, the Torch-Alamein pincer is out of the question and German control of the Med is only a matter of time, post-SU.

TMP bookmark: Hitler on Malta

[TheMarcksPlan]

TMP bookmark: ATL German bombing 1943

Germany will waste many more bombers attacking Britain than OTL

If we match my projected ATL deltas to LW production against OTL German bomber production (per USSBS: 6,509 and 8,589 in 42/43 respectively), we get ~12k more German bombers produced in '42/'43.

Let's suppose Germany expends all 12,000 extra bombers on night raids against England by the end of 1943, losing them to flak and nightfighters.

What's the impact on Britain? We need to estimate a few other parameters first:

• 1. LW ability to hit targets - in this case area targets in night raids.
• 2. Casualty rate of German bombers - therefrom sorties per lost bomber.
• 3. Bomb load per sortie.

Re (1): The Germans were terrible at hitting cities in OTL 1943 - 80% of bombs missed cities (GSWW v.7, p.408). During the 1944 "Baby Blitz" raids on London, this improved to 40% hit rate. The '44 raids were preceded by a long training program to re-orient LW pilots to strategic bombing (GSWW v.7, p.412-17). In ATL, this program would start earlier as the Eastern Front operations that withheld aircrews from it end by September '42. So the Germans should be about as "good" in ATL '43 as they were in OTL '44 (assuming they learn nothing from their greater experience of night bombing, which seems unlikely).

Re (2): German casualty rate in '43 raids on Britain was 5.6% - therefore 17.8 sorties per bomber if OTL rate holds.

Re (3): Let's be conservative and say 1t of bombs per sortie.

A little arithmetic gives us 213,600t (12,000 * 17.8 * 1) of bombs dropped on Britain, of which 40% - about 85k t - would hit a London-sized target.

The OTL Baby Blitz killed 1,556 with 1.3% of ATL bombload, here we'd expect >100,000 British dead.

It's also near certain that German accuracy would improve with experience - it would devote more aircraft to pathfinding and target marking than in OTL Baby Blitz, for example (see GSWW v.7, p.418 - "Pathfinder forces were too weak").

It's still a waste of German resources but it's not meaningless. War weariness in Britain would increase, building pressure to end an unwinnable war going into 1944, when a much larger and longer V-weapons offensive could render London practically uninhabitable.

What's more, the economic impact would come - as with Germany in the period - primarily from the diversion of resources: providing housing/furniture/etc. for bombed-out families, building more AA guns and ammo, holding back more Mosquitoes and other AC as night-fighters, dispersing production.

Finally, the OTL Baby Blitz's failure - its high cost for little result - contributed to scaled back bomber production and LW's reliance on the more economically efficient V-1 for retaliation. ATL '43 Blitz would likely have a similar effect, leading to earlier German focus on fighters.

[Politician01]

Don't you:

a) have to explain what those "factors" are? and

If you were here for anything else than nagging, you would have seen than on page 4 of this thread I laid out a detailed scenario what changes in 41/42 would have resulted in a Soviet cease-fire. Now you might attack this scenario - it however does not change the fact that it is there and that you just failed to read it and therefore you are just a troll derailing the thread. So please stop this childish behavior and and least skip through the thread before formulating some pseudo criticism.

b) acknowledge the Allied (US-UK) strategies are going to change to reflect whatever it is that changes to yield a)? and
c) acknowledge the possibility of separate peace by the USSR was why the Allies mounted the North Russia resupply convoys, as well as the Persian Corridor and North Pacific resupply operations, and
d) acknowledge the US and UK had multiple strategic options from 1941 onwards, all of which - all things being equal, of course - end up with an atomic bomb or two or three (at least, possibly more) targeted on Berlin sometime in 1945?

All of this has - to some extent - been allready answered in this thread:

B - Wallied strategies cannot change much. They have exactly two options - bombing - or invasion in the Med since by late 42 most of their forces are invested into this theatre - or both.

C- Irrelevant to the discussion

D- What are these "multiple" strategic options? Please enlighten us. They can bomb and hope that it amounts to something - or they can invade in the Med - thats it. As for the nuke "argument" - as allways it completely ignores the time period from early 1943 - late 1945. Only some 10 000 people knew about the bombs - no one knew if it would work. It also completely ignores realpolitics, the fact of German ATL AA defences and fighter forces and the fact that the US would want to finish of Japan hoping to avoid Downfall.

It also completely ignores that the Germans can change their tactics and strategies as well without having to fight the largest land war in human history.

It also completely ignores US public opinion. People do not want war - its the Politicians that want it. With Roosevelt on the loosing side, he might well loose the 1944 election to a Republican who promises to make peace with Germany and to concentrate on Japan. Regardless, he is dead in April 45 anyway, giving Truman the opportunity to conduct realpolitics.