Twilight of the Gods, was the question of just how far the Reich could realistically go without becoming a Nazi-Wank. This is not actually an easy question to answer. Very few people in 1939 would have believed that the French could be crushed so easily in 1940 - indeed, the Germans came alarmingly close to running out of ammunition during the Polish Campaign - and very few commentators in 1941 gave the Soviets more than six months before they too were crushed.
Post-war writers have added their own spin on matters. Books such as The Man in the High Castle and In The Presence of Mine Enemies assumed that an alternate Reich would invade and occupy America in the process of an inevitable rise to global supremacy. Others - including myself - predicted a resumption of the war between Germany and Britain (and America). But just how realistic are such scenarios?
The important point to bear in mind is that Hitler lived during what I believe to be the last great period of conquest. Hitler’s armies were armed and trained to race forward, seeking out the weak points in enemy defences and smashing through opposing armies before their enemies could react to the threat. Advances on such a scale were simply not possible during the Great War. At the same time, the threat of nuclear annihilation simply did not exist. The RAF could - and did - bomb Germany, but - even if chemical weapons had been deployed - their ability to bring Germany to its knees was practically non-existent. Defence planners believed that the bomber would always get through, yet ... so what?
By the time the 1960s rolled around, the armies were far more powerful - but, at the same time, more constrained. A Russian drive westward would almost certainly have triggered a nuclear response, when - if - NATO was unable to handle it. Russia would have been devastated, along with Western Europe. It is one of the many ironies of the Cold War that the US, which had a considerable nuclear supremacy, spent most of the war believing that it was fighting to catch up.
One may assume, of course, that Hitler was mad enough to consider launching a full-scale nuclear war. It would certainly fit into a story! But, at the same time, Hitler was rather more rational than we prefer to believe. Certainly, most of his pre-1944 decisions were rational based on what he knew at the time. Marching to Stalingrad was disastrous - we are told in hindsight - but it wouldn't have looked like a certain failure in 1943.
The other two major limitations on the Third Reich lie in their army and air force. Hitler had a fairly modern battle fleet - but it was grossly outnumbered by the British. (Adding the Italian Navy to the Reich doesn’t really tip the balance.) Hitler could - and did - threaten supply lines between Britain and her empire (and America) but he couldn't strike directly at Britain itself. Meanwhile, the Luftwaffe was largely a short-range striking force. The Germans never had a successful long-range heavy bomber, ensuring that large parts of Britain were immune to German attack (and America was completely out of range.) Any attempt to assess the limits of the Third Reich must take those factors into account.
So ... how far could Hitler have gone?
To the west, Operation Sealion was pretty much a pipe dream. Some authors have speculated that the invasion might have been possible, but the Germans really had too many limitations - a shortage of shipping, among others - to make Sealion anything other than a very risky gamble. Hitler simply could not get across the English Channel.
For this to change, Hitler would need to reshape his air and naval forces radically, following a strategy that would have no viable purpose other than the invasion of Britain. Even if the Hitler of 1938 was prepared to make the investment, long before France was crushed in 1940 and Sealion became necessary, such programs would very definitely change the political situation during the run up to the war.
[The idea that Hitler could have invaded America is so absurd not to require further discussion.]
Hitler presumably has no need to occupy either Spain or Portugal. Neither power was inclined to challenge the Third Reich overtly. However, he may well want to pressure the Spanish to take Gibraltar and the Portuguese to break ties with Britain. Both steps could be taken, at considerable economic cost to both Spain or Portugal. In such an eventuality, one might see Hitler facing his own version of the Peninsula War.
To the south, the problem facing Hitler is logistics. The Germans might have been better than the British at desert warfare, but Rommel was always operating on a shoestring. Hitler always saw the desert war as a sideshow, rather than a potential way to bring the British to heel. And again, from his point of view, he was right. Nazi gains in the Middle East would always be tenuous as long as the British remained undefeated and Soviet Russia loomed to the east.
Taking Malta during 1940 would have been easy - even the Italians could probably have done it. (Indeed, a timeline where Germany invades Malta instead of Crete might lead to German dominance in the region.) Malta would serve as a giant airbase, allowing the Germans to drive the Royal Navy out of the region and ship additional supplies to Rommel. Thus reinforced, Rommel might have been able to push forward to Suez and drive into Palestine, creating a massive humanitarian crisis. Scenting British weakness, the Arabs would rise in revolt, enthusiastically supporting the Germans. As the British position crumbled, the Germans would probably be able to cow the Saudis (unless American forces arrived in time to dare Hitler to attack them.) They’d certainly have access to a great deal of oil
Depending on precisely when this happened, Turkey and Iran would both become very important. Turkey would have good reason to secure Northern Iraq before the Germans could arrive - a long-standing Turkish objective - while Iran would probably try to remain neutral or even join the Germans. (Iran was occupied in August 1941, but if the Germans pushed forward hard Iran might rise in revolt.) At that point, the Germans might see value in Iran as a buffer state.
Logistics would remain a major headache for the Germans. Marching all the way into India would seem the ideal way to end the war, but their logistics would need to be built up heavily before they could make their move.
To the east, just how far could the Germans go?
Hitler did come very close to taking Moscow in 1941 (this has, obviously, been hotly debated.) Taking Moscow would not just have dealt a crippling blow to Russian morale, it would also have cost the Russians a large part of their transport infrastructure and the bureaucratic system that kept the USSR running. It’s tempting to joke that shooting the bureaucrats would make the USSR more efficient, but it’s wartime - they need that command economy. Worse, perhaps, large reserves of manpower would be lost. Stalin, assuming he survives the battle, would have to rely on troops drawn from more restive parts of the USSR, troops who might not be remotely trustworthy. And if the Germans make even the slightest attempt to treat the natives well, even as a tactical measure, they are likely to win hundreds of thousands of adherents.
This was, I suspect, Germany’s last chance to win the war outright. Taking Stalingrad in 1942/43 would have certainly hurt the Russians, but it wouldn't have been enough to keep the Americans from bombing Germany heavily and continuing to supply the Russians with Lend Lease, even if there was no second front. By 1945, America would have atomic bombs - if only a handful. Dropping those bombs on Germany would do immense damage, possibly prompting the military to overthrow Hitler and order a surrender. At that point, the Reich would be doomed.
So ... let us assume a Reich that reaches from the French coastline to the Urals and the border of Iran. How long can they actually keep it?
That is not, of course, an easy question to answer. Taking territory is one thing, but controlling it indefinitely is quite another. The Germans would be no less willing than the Soviet Union to exterminate vast numbers of people or forcibly relocate them to places well out of the way. On the other hand, controlling places like Greece and France would be difficult. Would the French go quiet if the Germans offered them a liveable peace? Or would the French resistance grow stronger as the German grip tightened?
The Germans would, I suspect, face a great deal of partisan warfare in both Russia and the Middle East, if only because they won’t be offering the natives any sort of liveable peace. Hitler might have been happy to work with the Arabs - the Arabs would probably exterminate the Jews in Palestine for him - but he didn’t see them as anything more than Untermenschen. I would expect the Nazi grip to tighten, just to make sure the oil keeps flowing to Germany, and eventually a bid to outright exterminate the locals.
Hitler would need to boost his population by any means necessary. On one hand, the Nazi plans to encourage a growing birth-rate would have time to bed in, probably giving Nazi Germany a baby-boom. On the other, large numbers of young men will have been killed during the war, probably forcing the Germans to use young women in industries rather than bringing up children. (The Nazis didn't want women to work outside the homes, but they may have to compromise if there is a major manpower shortage.) The kidnapping program - in which the Nazis took ‘Aryan’ children from their parents and gave them to good Germans to raise - would probably pick up speed. So too would attempts to convince ‘Aryan’ westerners - like Norwegians - that they were actually Germanic.
The German economy is an interesting question. Historically, despite waging war against most of the world, the Nazis didn't embrace a command economy until 1942, when Speer was appointed as Minister of Armaments. Speer consolidated power over the German economy despite bitter opposition. I’ve actually heard it speculated that Speer’s reforms came six months too late to save Germany. Assuming that Speer’s reforms are not seen as necessary in this timeline, what will happen to the German economy? I suspect it might well remain a fragmented mess of bailiwicks, controlled by the various German ministries, rather than a single organised whole.
Nazi Germany was constantly pushing the limits of technology - rockets and jet aircraft in particular - but I doubt the US will remain behind for long. The real question would be German mass production. Using slave labour in factories which require precision and adherence to detail is asking for trouble. Choosing to ignore ‘Jewish’ science would cripple the Reich’s nuclear program. As technology advances, the Reich might well start falling behind.
Education, in fact, is likely to have a dangerous long-term effect on the Reich. Children were not taught to think for themselves and question authority. The SS wouldn't see any difference between questioning orthodox science and questioning the Reich itself. Children were expected to join the Hitler Youth and excel in manly pursuits - creating a body of part-trained manpower for the military - rather than study science. Matters would not be helped by the Reich’s triumph seemingly ‘proving’ Hitler’s nuttier racial theories. Reasoning from incorrect - and absurd - premises would lead future scientists to incorrect conclusions.
Overall, just how long would the Reich actually last?
Hitler will die at some point, shortly after the war. His health was already failing before he killed himself in OTL. Unless he does something to create a long-term governing structure for the Reich, there is almost certainly going to be a major dispute over the succession, not least because Hitler liked playing his subordinates off against one another. Himmler would seem to be the heir presumptive, but there would be other candidates. Speer? Goering? Or someone who rose in power past the end of 1945? It’s very tempting to imagine a civil war following the death of Hitler, as the SS attempts to take complete control and the other factions actively resist it.
A nightmare would have descended across the Reich. Even in Germany, Germans would not be safe from the SS - war-wounded veterans, amongst others, would be targeted for elimination. Entire populations deemed inferior would be exterminated. Millions upon millions would be ruthlessly slaughtered or enslaved. It would be the end of the world as they knew it.
But would this Reich last for a thousand years?
That, of course, is the question. I believe the answer is very definitely no, barring a considerable - and unlikely - degree of political reform. The economy would grow weaker and weaker - while the US moved ahead - while no application of military force would be able to hide the Reich’s underlying weaknesses. Would there be a semi-peaceful collapse, as Harry Turtledove speculated, or my outright civil war?
Perhaps we should be grateful that we will never know.
* * *