This post gives an overview of various PoDs that might help Nazi Germany win the war. Including their necessary conditions, how they'll influence the war, and how high I guesstimate the probability that they're going to happen.
If I have to heap coincidence and dumb luck for this, I don't mind. Not even if I literally arrive at a chance of one in a million. Not because we are on Discworld, it's the principle of the thing. And admit it: It's somehow very calming to know that Adolf Nazi's chances to win are that low.
Also consider: The shorter the allowed window of opportunity, the smaller the probability of this event happening.
Note: Two independent 50/50 chances usually make a chance of 25%. Rolling eight sixes in a row'd have a chance of less than one in a million. (I'd liked it better if it had been six or seven times.) But if the chances are dependent, things look different. If e.g. Canaris' machinations are discovered, the chances for Spain entering the war grow (because Franco had been misinformed by the Abwehr). Also, Heydrich might survive. And the attack on Crete'd go different if the Nazis knew that British troops there were three times stronger than what Canaris had claimed. And if the BEF was defeated at Dunkirk, practically the whole war changes for Britain, since they'll lack experienced troops now - especially to raise and train more troops!
Only allowed percentages: <1, 1, 2.5, 5, 10, 20, 30, 50, 70, 80, 90, 95, 98, 99, >99.
Oh, and every PoD has to happen in May 1940 or afterwards - with the "Sickle cut", Adolf Nazi already got veeery lucky, it'd be very hard to top that.
And Operation (Sea) Lion is right out, of course.
Alternate Axis members:
- Spain: Depends on two questions: Do they know that Canaris gave them information that was wrong? And will they join the war for a short, local campaign (Operation Felix, restricted to Gibraltar), or something bigger?
* Canaris uncovered: 20-30 for a Gibraltar campaign, 5-10 for a bigger one.
* Otherwise: <5/<1 respectively.
- Bulgaria (vs. Soviet Union): Improbable. The population didn't want war with the Russians. (That's why they only made war against other Allied nations.) <5.
- Turkey: <5%. Even then, this wasn't the Turkey of today - their military strength rather was comparable to Yugoslavia, if not worse. Also, the answer'd depend on whether they'd have to fight the Brits, the Soviets, or both.
- Argentina: <1. Even for a local campaign to take the Falklands, nothing more, <5.
- Japan (vs. Soviet Union): <5. Even the chance for an indicent after Nomonhan <20. Especially interesting would be a strike against the Trans-Siberian railroad, after L&L would be extended to the Soviet Union.
- South Africa: <1
- Soviet Union (vs. Brits): <20
- Persia/Iran, Iraq, Egypt, Saudi-Arabia: Unless the Wehrmacht is already standing near the big population centers, an uprising is likely to fail. Unless British presence was weaker...
- India: A big-scale uprising in India might easily tip the scales of the World War. Despite of Bose and the like, the probability seems to be low, though.
Alternate Nazi campaigns:
- Operation Felix: Attack on Gibraltar. Needs cooperation of Spain (see above). Hence, improbable. But if Spain cooperated: >50
- Operation Isabella: Attack on Portugal. Also needs cooperation of Spain. Even more improbable than Felix.
- Operation Polar fox: Attack on Sweden. Probably doable, but during the war, there's no visible gain. Sweden already delivered iron ore to Germany, a war wasn't necessary. Maybe towards the end of the war, when the war with the strongest opponents is over, to complete the "Greater Germanic Reich".
- Operation Fir tree: Attack on Switzerland. May not look like it, but would be a disaster for the Nazis. Switzerland was able to mobilize 500,000 men, had great defenses in the mountains, and was willing to fight on even if the Germans took the lower parts of the country with the big cities. Hence, improbable.
- Operation Hercules: Attack on Malta. Needs cooperation of fascist Italy. Mussolini's pride would be hurt if his armed forces didn't manage to take even little Malta. Also, the Wehrmacht would needs paratroopers for this, most of which were lost on Crete in OTL.
- Operation Gertrud: Attack on Turkey. Needs cooperation of Bulgaria and/or the Soviet Union, or control of Greece. All of which is possible. As said above, the Turkish army wasn't very strong during World War 2. OTOH, the bad railway network of Turkey (a good part was still single-track) would delay Wehrmacht advances.
- Earlier Operation Barbarossa: Was originally planned for early May, not late June as in OTL. Looks promising, but there's a different danger: The Rasputitsa, the early mud season, which took especially long in early 1941. In fact, OTL invasion didn't start too late for this. Hence possible, but not promising.
- Mega-Dieppe: In OTL, the Allies used about 10,000 soldiers for the Dieppe raid and lost more than 6,000 of them. The lessons learned from this were valuable, though. But what if the Allies had decided to start a bigger invasion (albeit smaller than Overlord) and it had been a failure as well? (Wouldn't necessarily have to happen at Dieppe. Any coastal place controlled by the Nazis and their satellites from Narvik to Casablanca would work.)
- Torch fails: Similar as the above. It would be necessary that someone close to the top will make very bad mistakes. Like sending troops to North Africa which are too weak and hence might be defeated by the Wehrmacht. And even that seems only probable if the war in the East has ended until then. Or never started to begin with. Also, the Nazis would have to control the Med.
- Nazis bomb Baku: Which would lead to the Soviet Union losing most of the oil it needs for tanks and airplanes, making them useless. However, the Luftwaffe would need some airparts in reach - either in a) eastern Turkey, b) northern Iran, or c) Syria and Iraq. At the very least not impossible, esp. c). After all, Syria was under control of Vichy France, and there was the uprising in Iraq.
- Nazis strike Murmansk/the railroad there: That'd have to be done by general Dietl's mountaineer troops. Might cut off the Soviet Union's most important warm-water harbor, hence L&L goods wouldn't end up where they'd be needed.
- Nazis take Cyprus: With the precondition that the Allies don't have strong navy or airforce units in the Eastern Mediterranean. Also, the Nazis would need paratroopers for this (see Operation Hercules above).
- Nazis attack and defeat the BEF at Dunkirk: 50 for an attack. Somewhat less for a successful attack (total destruction of the BEF at lower losses for the Wehrmacht). Would have enormous consequences for the rest of the war, as it'd become harder for Britain to raise and train new troops. Hence, this PoD might influence many other on this page.
- At Operation Taifun, more troops from Heeresgruppe North are sent to Moscow instead: Even if the city won't fall, many of the important railways might be cut off, making it harder for the Red Army to move troops. Tula with its arms factories might fall even more easily. It's just q question of one decision...
- In August '41, OKH commits its reserve mechanized divisions to AGS's left wing (aka Gornostaipol option): Comparably small impact, but it might count towards a victory.
- Luftwaffe bombs British airports instead of cities: They might win the Battle of Britain - of course, Sealion would still be out. At the very least, the Royal Air Force would be seriously weakened. But for this, the "führer" would have to change his opinion, or Göring would have to be competent.
- Japanese attack in three waves at Pearl Harbor.
Alternate Nazi personnel:
- Fritz Todt doesn't die: Which also means that Albert Speer won't get his job. Now who might be better to expand German arms production? And whether that'd be good or bad for the Nazis is a different question.
- Reinhard Heydrich doesn't die: Very useful esp. for "state within a state" of the SS. As they said, Himmler's brain was Heydrich. He might take over bigger tasks after his stint in Prague. Maybe even replace Himmler?
- Wilhelm Canaris removed as head of Abwehr: Expect many changes, as he double-crossed the Nazi regime. E.g. gave Francisco Franco false intelligence, so the latter wouldn't join the war. Also, his successor might be named Heydrich - which means he might survive.
- Hermann Göring dies: Then, the Luftwaffe would be lead by someone who isn't addicted to morphine and may not make that many empty promises what he can do. Who's the successor? Robert Ritter von Greim? Albert Kesselring? Hugo Sperrle? Wolfram von Richthofen? Erhard Milch was half-Jewish, hence unacceptable for other Nazis as soon as Göring'd stop keeping this under cover.
- Heinrich Himmler dies: Which would put Heydrich to the top of the SS, probably. (That is, if he wasn't assassinated, see above.) And many stupid decisions by Himmler would be avoided. But from which event would Himmler die?
- Ernst Udet doesn't commit suicide: As a flying ace he was very competent, but not so much managing the Luftwaffe. Hence his survival wouldn't really be an improvement.
- Eduard Dietl doesn't die: Then, a competent General of the mountaineers survives, who even was allowed to get away with speaking a honest word with the "Führer". However, he died in 1944, and at that time the war should already be decided in favor of the Nazis - or their victory is impossible.
- Isoroku Yamamoto isn't shot down: So the Japanese keep their most competent Admiral. However, the Alliied had broken the secret code of the Japanese, so the Scenario might repeat - unless Yamamoto avoided even getting close to alliied airplanes.
Alternate Nazi technology:
- Konrad Zuse's computers: In OTL, Albert Speer thought this might be a good idea and even told the "Führer" about it. Who only said that he didn't need a computer to win the war.
- Nazi nukes:
- More/better Messerschmitt planes:
- Messerschmitt planes used as fighters, not bombers: That'd be an example of "better planes".
- Enigma security notched up: Might happen in connection with Canaris being uncovered.
- More/better Tigers/Panthers/Jagdpanthers/Königstigers:
- Thermobaric bomb by Mario Zippermayr: Potentially devastating, but needed until 1943 in our history to be tested.
- US Army doesn't copy the jerrycan: Half of the supplies (weight-wise) was fuel, after all. Before they had the jerrycan, much fuel was wasted simply because the other canisters leaked or were hard to fill. - Just for completeness sake mentioned: US engineer Paul Pleiss had copied the design in 1939 already. As said, only later PoDs allowed. But feel free to copy this if you want a PoD dealing with logistics.
Alternate Nazi economy:
- Nazis allow more free market: Promising re: impact, but doesn't really fit in with Nazi ideology. Maybe if they received enough bribes...
- Operation Desert: Nazis develop oil shale technology. In the long run promising, but the local project wasn't very profitable.
- Nazis use more assembly lines: Would help a lot. The problem is: Nazis thought this was "slave work", nothing you could bear on the "Aryan" workers. (Forced laborers might be a different thing, though.)
Alternate deaths:
- Franklin D. Roosevelt: The driving force against Adolf Nazi in US politics. Hard to say who'd be able to replace him. Doesn't mean the Nazis should start to provoke an FDR-less US.
- Winston Churchill: The driving force against Adolf Nazi in British politics. Again, hard to say who'd be able to replace him.
- Joseph Stalin: Per se, many might lead the war better, esp. the military and in the early stage of the Nazi-Soviet war. Unfortunately, his death might throw the Soviet Union into chaos at the wrong moment.
- Charles de Gaulle: The driving force against Adolf Nazi in Free French politics. Again, hard to say who'd be able to replace him.
- Chiang Kai-shek: The dictator of a corrupt regime, but seems to be the only one who is holding the country together. Without him, the Chinese republic might fall apart into chaos, with every warlord proclaiming himself as the new ruler. Yet again, hard to say who'd be able to replace him.
- Dwight D. Eisenhower: One of the most competent generals of the US who had his troops advance slowly and patiently without trying something risky which the Wehrmacht might have used for a crazy but promising plan.
- George Patton: Another competent US general, even if he loved the war a bit too much, for being popular with his men and courageous. And neither afraid nor ashamed of reading his opponent's books.
- Georgy Zhukov: One of the most competent Soviet generals.
Other:
- No declaration of war on the US: When this happened in OTL, the odds of winning the war were minuscule already. The purpose of this decision, as absurd it may seem: To be able to fight with submarines everywhere in the Atlantic, to intercept L&L ships, before the war is lost. In TTL, this might be different. >80
- Wehrmacht during Barbarossa better prepared for the Russian winter. Strangely, planners had warned about this, but the leadership didn't care. Especially odd because some high-ranked Nazis had actually lived in Russia, including Rosenberg. Who was even more reality-impaired than his boss, though. Impact: Many German casualties could be avoided, so quite high. Probability: Still low.
- Better treatment of the people of the Soviet Union. There was a lot of anti-Communism around. But as many have pointed out, it'd mean that we need Nazis who aren't Nazis. Improbable.
- Volga Germans are settled in the Reich before Barbarossa (seriously, was nobody thinking about them? So much about caring about your "Volksgenossen"...): This might give Germany one more division, maybe more. Not much, but it might matter.
- Separate peace: Veeery tricky, of course. And practically impossible as soon as the Allies agree not to make this. So it'd have to happen before that, obviously.
* With Western Allies: Mussolini might negotiate one in 1940, the Brits at least had thought about that. Still improbable. Alternatively, the USA might help to negotiate, but that's improbable too.
* With Stalin: Only relevant after the start of "Operation Fritz/Barbarossa".
- A treaty with Vichy France to allow transporting goods through Tunisia, to secure the supplying of troops in Libya and Egypt. In our history, such a treaty was planned, but never signed.
- Submarines being more successful. Harris used this as his PoD in "Fatherland": The subs destroy so many ships bringing food to Britain, at the end they have to make peace in 1944. Churchill also wrote that the subs were his biggest worry... (This one's Enigma-related.) Of course, the Nazis can't create either subs or their commanders by magic.
- The Katyn massacre gets discovered and published by the Nazis, discrediting Stalin before the British-Soviet alliance is standing strong. Of course, this discovery wouldn't make Nazi Germany a bit less dangerous, and the Brits would know that.
- Adolf Nazi stops interfering so much in the war. This might actually happen if the war went better - for which other PoDs would be necessary.