So you're eschewing the massive surprise attack scenario per Barbarossa? Were you thinking of something like skirmishes or proxy wars around border states like Finland or Romania?
I'm thinking of the following scenario: both Stalin and Goering are expecting and preparing for a major war sometime around 1941-42, Britain wishes peace in Europe but is growing more and more disillusioned. Since Germany ITTL didn't invade Bohemia-Moravia, has worked hard to build British sympathy for his position in Poland, and goes for a moderate peace settlement in Poland (annexations and satellization), London gets Berlin get away with a limited Polish war.
Afterwards Germany lies relatively low (greater political moderation), Stalin gets more aggressive (he does not get either a M-R pact nor a Western alliance, and war with Germany is only narrowly avoided over the partition of Poland, so he sees the need to expand Soviet power base and prepare for a preemptive war). Soviet encroachments and limited wars in Finland, Romania, Bulgaria, and Turkey gradually shift British opinion towards seeing Stalin as the main threat to peace in Europe (reverse OTL scenario). Eventually, Stalin (like Hitler OTL) overreaches himself and Britain goes for war. This plunges Germany into war before Berlin expected it to (in a way, I reverse the 1939 Poland scenario and let it occur sometime in 1940-41 over Finland/Romania/Turkey). Like 1939 OTL, ITTL all major powers expected the war to erupt eventually and planned for it but it occurs before their preparations were any really complete.
No, I just meant that as long as they're fully independent with a large army, you'll need to keep forces in the West for defence "just in case", even if they're friendly. Especially if they get to upgrade and adapt modern tactics.
Yep, that's why I expect the conflict to be relatively bloody and prolonged, and the Allies to wear down the Soviets gradually, not through a swift successful Barbarossa.
I suppose you're butterflying away the Nazi uninterest for atomics early on, the faulty premises (bad calculations for the critical mass, etc) and Heisenberg's bad management? Perhaps a dedicated military effort, with a Brigadier Groves analogue to keep him on the right track? And Meitner staying, with less anti-Semitism, providing better calculations to start with?
I'm (tentatively) posing the following scenario: since the political distance (and distrust) between British conservativism and an moderate fascist-authoritarian Germany are not as great as between UK and URSS, and the USA are neutral, once UK and Germany are full wartime allies, to some degree the same kind of data-sharing that occurred between UK and USA OTL occurs between British and German teams. This jump-starts the German team back on the right track, but since the two Allies don't trust each other THAT much, TTL Project Manhattan occurs as a joint effort. Since neither UK nor Germany can afford to expend as much as the USA on the project, they are slightly delayed, but this is partially compensated by the fact that both teams share data at any step.
Since I've picked a relatively late PoD for Germany, for various reasons (Hitler dies soon after Munich, Goering takes over and gradually steers the regime back from extreme genocidal racism to moderate fascist-authoritarian imperialism), I've been so far unable to provide any decent solution to the "Jewish problem", which is realistic for the gradual political evolution of Germany, within the TL's constraints before WWII, other than "they bribe the British to dump their Jews in some corner of the British Empire". So Meitner is sadly probably an emigree now. However, since the leadership is saner, they may be willing to make some exceptions for people like her, or the vagaries of war mean that Meiner becomes a member of the British teams (most ex-German Jews are British subjects now). Granted, things happen in the scenario that make radical Nazist views, including extreme antisemitism, fall out of favor more and more with the regime (the British alliance itself is one, another is a reverse Nazist Valkuria). But I strive to make things realistic for Germany, and walk back from Hitler's extremism one step at a time on a tighttrope walk spurred by hard realities, not Goering and co. wake up one day and are Jew-hugging democratics for no good reason.
Then there might be trouble mobilising opinion and what have you.
"Let's keep Europe free from Bolshevism" once the war erupts is IMO a rallying cry that, with Hitler and the Lebenstraum safely in the grave, works fine from London to Berlin. It almost worked OTL, until Hitler's genocidal racism put the lie to it.
Still, it makes the military contest more even. But this also depends on how you pose the initial attack, and when; the Soviets will have time for massive build-ups and reorganisations if you postpone the major hostilities for too long.
Discussing such issues is the very reason I started the thread. Let's say that in all cases it does not go beyond early 1941. But the critical issue over the DoW schedule is when the British get fed up with Stalin's aggressions and choose war (they must do so by their own free choice, or the scenario won't work). Germany's greater political savy makes Stalin's brutish approach get stark by contrast, and OTL Western opinion got quite nagry at him for Finland, but ITTL Britain has just let Germany beat Poland down (although the scenario provides plenty of justification like Poland's fate was somewhat well-deserved), so it probably takes some steps in the chain of Soviet aggressions to make the UK build up the resolution that THIS dictator needs to be brought down by whatever means (although I assume some leeway by the fact that to the 30s Britons moderate polite fascism does not look as alien as Stalinism).
Let's assume Finland, then Romania, then encroachments in Bulgaria and Turkey, sprinkled with some good old Communist subversion in India. When the UK says enough ?
Might have negative consequences for logistics, as the forces can't "live off the land". OTOH, it reduces interference from partisans etc.
And encourages the natives that would be partisans, to enroll for the Allies instead.
Another note to consider might be what this does for German discipline. The OTL Heer's soldiers got more and more unruly as the war progressed, and there appears to be agreement that this was in large part due to the general lawlessness in the East; the brutalisation and disregard for law spread from just terrorising the populace to causing general disciplinary problems.
Yep, I suppose that might eventually become a problem for any army (Iraq, anyone ?), only compounded by the fact that the Wehrmacht can only become realistically "nice" to a degree (although the sane leadership acknowledges the huge value of native collaboration, so it reins extreme abuses in). OTOH, I point out to the fact that ITTL, the Germans have plans to win the allegiance of the natives, not exterminate them, so there will be way less of a partisan problem, and this greately reduces the vicious cycle that causes the brutalization you mention. Also be mindful there will be plenty of British, Italian, Swedish, Turkish etc. boots on the Russian ground.
Hm, point. Though neither country will be able to pay for full imports indefinitely in any case, without Lend-Lease.
Who says there won't any American Land-Lease ITTL ??? Think, for one, without a war in early 1940 in Europe, Roosevelt's whole justification for claiming a third term melts away and the more Britain and Germany close ransk to contain Communism, the more his anti-fascist, anti-German foreign policy agenda alienates the American public. He loses the 1940 nomination or election to some Republican or moderate Democrat, and the new Administration will be most happy to shower heroic anti-communist crusader Britain with Land-Lease. True, given extreme American isolationism in the period, it is IMO extremely difficult to visualize a Pearl Harbor like scenario that would bring the USA to DoW Stalin (he was paranoid, not megalomanic, so while it's easy to make him unwittingly forge just the anti-communist alliance he feared, I really do not see him DoWing the USA for no good reason like Hitler did) so I see the USA staying neutral, maybe fighting a separate war to Japan and just sending Land-Lease and financial help to Europe.