Why Nazi Germany Lost WW2 - an analysis

I think the issue with the debate about Moscow and Typhoon and all of that is that many people base their knowledge on this issue by reading the memoirs of their favourite generals, such as Manstein or Guderian. The issue with that is that, while those two were both perfectly competent, their job was deal with the military aspects of the war, and even then, on a relatively small section of the front. The result is that they often miss the big economic picture of the war.

Guderian’s endless rant about how Hitler lost the war by not hyperfocusing on Moscow is a prime example:
Hitler made the right call when he ordered Guderian to head South. The Red Army would be sure to fiercely defend Moscow, and even if the Germans managed to take it, it would have been reduced to ruins just like Kiev and Stalingrad where. If the Germans would had captured Moscow, it would be a great symbolic victory to be sure, but strategically, they would just have wasted time they couldn’t afford to waste.

If Hitler had done what Guderian wanted to do, and continued pushing towards Moscow, then the Germans would have lost the war even quicker then they actually did. Because Hitler didn’t listen to Guderian, at least Germany managed to take some Caucasian oil fields and extract some oil from them before they were pushed back.

The Oil from the Caucasus was absolutely necessary to continue the war. If the Caucasus didn’t fall by late 41/ Early 42, then the German war machine would be grounded to a halt and they would lose almost all offensive striking capability.

As the situation stood in 1941, the Caucasus were vital to continue the war effort. Moscow wasn’t.

Hitler personally considered Moscow to be “not very important.” and he was, as much as I hate to admit it, absolutely correct in that assessment. Moscow was a sideshow, symbolically important but strategically nonessential.

"If Germany succeeds in taking Moscow that is obviously a grave disappointment for us, but it by no means disrupts our grand strategy. Germany would gain accommodation, but that alone will not win the war. The only thing that matters is oil. As we remember, Germany kept harping on about her own urgent oil problems
in her economic bargaining with us from 1939 to 1941. So we have to do all we can to make Germany increase her oil consumption, and to keep the German armies out of the Caucasus.
- Soviet Field Marshal Semyon Timoshenko

That Caucasus were all that mattered; Moscow, Leningrad, Smolensk, they were just a waste of time and effort. To put it a bit bluntly, the OKH was strategically and economically illiterate. They focused on symbolic nonsense rather than strategic necessities.

The Stavka, unlike the OKH, understood modern war and it’s economic realities. You can kill a hundred million enemy soldiers, eviscerate a hundred enemy armies, and capture four dozen capitals, but to actually win the war, you need resources, you need oil. The OKH didn’t understand that, and as such, they lost the war.

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Germany failed to capture a significant portion of the Caucasian oil fields and those it did were so effectively sabotaged by the Russians as to render them useless, forcing the Germans to essentially start over from scratch. From The Caucuses 1942-1943 Kleist’s Race for Oil by Robert Forcyzk, the Technical Brigade Mineralöl, the organisation set up by the Germans to extract oil from the captured oil fields managed to extract a grand total of about 1,000 tons of oil before they were forced to abandon the region due to the Soviet victory at Stalingrad. It was estimated that it would take until the end of 1943 to restore significant production to the region.

Another factor that was starting to seriously affect Germany’s ability to wage war on the Eastern Front by this time was a shortage of manpower. Germany had already mobilised around 85% of its available manpower at the start of Barbarossa. By 1943, replacements could only come from returning recovered wounded soldiers to the front, by taking skilled workers from the war economy or by conscripting young men turning 18. The latter gave them around 600,000 recruits per year but the Soviets, with a larger population and a high birth rate in the 1920s could count on around 4 times that number. Any plan involving capturing resources to sustain a long war of attrition had to deal with the fact that just to maintain the status quo, the Wehrmacht had to inflict a 4:1 loss ratio on the Red Army.

Just as capturing land or wiping out armies will not knock the Soviets out of the war, neither will capturing natural resources as the place is so vast they can simply find new sources of production or increase output from existing ones elsewhere. While the Germans never captured Grozny or Baku, the main centres of oil production, they did cause enough disruption to dramatically reduce production there. The Soviets responded by expanding drilling operations in the Urals and Siberia instead and the Soviet war economy kept ticking along. See http://karbuz.blogspot.com.au/2006/10/oil-logistics-lesson-from-wwii-3.html.

The Germans needed some way to knock the Soviets out of the war before their superior numbers and resources simply ground them down. This may well have been impossible but the Germans needed to find something that they could capture or destroy that would hurt the Soviets badly enough to compel them to negotiate. Taking Moscow might not be enough, and indeed it may well have been beyond the capabilities of the Wehrmacht to get there in 1941, but IMO it was the best bet they had.

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I agree with many above points, however there are other things to consider.

Regarding taking Moscow issues one has to consider the following:

  • After turning Guderian, etc to Kiev, it was Hitler who order them back to attack Moscow.
    Hitler could have told them to continue going south for oil areas (or even half to go south). Waste of valuable fuel to go south first and then going back to towards Moscow again.

  • Hitler supposedly planned to wipe the city of Moscow off the map and to put a big reservoir over the area to prevent it being used ever again. Also, if the city of Moscow surrender to the German Army, Hitler had given an order not to accept the it. I think this is one of reasons why Hitler order them back to Moscow.
    (My source for not aceepting the surrender and what was to be done with Moscow above is the U.K. T.V. show “Battlefield” episode ‘Battle for Russia’ about 1:42:30 to 1:42:55 mark or so. Someone has it up now YouTube, but I have the DVD and seen it many times on T.V.).

  • The reason some historians suggest that the success of Operation Blue (summer of 42) - advance on Stalingrad and Caucasus oil was as U.S.S.R. figured Germans would attack towards Moscow again. (Roughly 50% of Russian Army was around Moscow areas and only 10% was in the south).
    Thus, the attack Moscow can be said to have a value in 1941 to. Also, if U.S.S.R picked up on Germans were only going for the south then Russians could have put much more troops in the south then they actually did.

  • Moscow is unimportant, correct, but, it was a important political, Militarily, a big transport hub, and had some factories. Thus, important just like Stalingrad become important to Hitler in 42. Stalingrad has no Oil, but Hitler wanted it and waste time, men and fuel on it.
    Or to put it another way the same problem that Kiev caused the Germans in 41 would have happened in the center if they attacked only in the south in 41. Not mention the northern front.
    So you can blame the German Army, but Hitler is one the one who kept changing his mind on things, so blame can go up to top to.

Do not get me wrong, I like it and I have heard others say it to, regarding attacking to the south only. However, there are problems with it and some suggest to that might not have worked.
One last point is Blitzkrieg strength is to attack a weak point, if you only go south for the Oil fields only, it limits the front and the number of weak points dramatically. And one could end up doing Kursk style battle in the south in 41, by that I mean they know where you are going, can build all or most defences lines in the south, etc.

The Soviets had indeed destroyed the Oil Fields very thoroughly, and it was indeed a massive headache for the Germans to get them up and running again. This is why you can make the case that Hitler’s “Stand Fast” order was the correct choice - It made sense to not give up any of the oil. Either way, it was still better than nothing.

I think this sort of misses the point though. The thing is that in order to bypass the war of attrition and Blitz the enemy out of the war, they needed oil. The purpose of capturing the oil wasn’t so that they could then sit still and wage a stalemate war á la World War I. The purpose of capturing the oil was to that they could fight a mobile war again. So, the purpose of capturing the Oil was not to sustain a war of attrition, but rather to revitalize the German army so that they could smash through once again and do what they did best, fight a war of movement.

A war of movement, with Tank blitzes and and Lightning strikes needs fuel to be done. Capturing the Caucasus was the only way to avoid a war of attrition.

Capturing the Caucasus wouldn’t knock the Soviets out of the war. Capturing the Caucasus would prevent the Wehrmacht from losing the war. That’s the key difference. The Wehrmacht wasn’t fighting to win, they were fighting to not lose. And in order to not lose, they needed that oil. Otherwise their offensive capabilities would be kaput.

As aforementioned, my point is that the only way Germany could had knocked the Soviets out of the war was by taking the Caucasus. Taking the Caucasus and their oil fields wouldn’t had been the end, but rather the means to an end. It was only by taking the oil that they stood any chance of beating the Soviets. That’s why they needed to focus on capturing the Oil first and foremost, and then reignite the push towards Moscow and Leningrad and the other major cities.

They could take the Caucasus without Leningrad and Moscow, but they couldn’t take Leningrad and Moscow without the Caucasus.


Hitler might have issued the orders for Typhoon but it was the Wehrmacht’s idea and it was they who pushed hard to do it.

An advance on the Caucuses in 1941 runs into the same old problems of logistics. The distance covered by Army Group A in 1942 as it advanced into the Caucuses was at least as great as Army Group South had advanced in 1941.

There are a couple of reasons why the Soviets were so weak in the South in 1942. Those troops outside Moscow weren’t exactly sitting around waiting for the Germans to attack. They were involved in a gigantic series of battles of attrition with Army Group Centre that the Soviets came to refer to as the Rzhev Meatgrinder. Soviet armies in the South also took horrendous losses at the Second Battle of Kharkov that pretty much opened the door for Case Blue shortly after.

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Is oil really the limiting factor though for the Germans in 1943? Look at this a different way. Let’s say for the sake of argument that the Germans somehow manage to hold Stalingrad and Maikop in 1942. What do they do next?

  • Indeed, Hitler was too emotional for his own good. He was correct about the Oil, but hey, even a broken clock shows the right time twice a day. Hitler certainly wasn’t a strategic genius, but he just so happened to be correct in his first order to Guderian.

  • Aside from not being a Strategic Mastermind, Hitler was also a ideologue. Many people (Including myself) have made the case that Hitler sort of had to invade the Soviet Union if he wanted to continue the war with Britain. The only other option was taking the Fritz Todt route and using France, Belgium, Denmark, Norway and the Netherlands as bargaining chips to make peace with England. But even though many people, including myself, can see the rational reasoning behind the invasion of the Soviet Union, I think it’s undeniable that Hitler was motivated by Ideological fury more than my Strategic foresight. Same thing goes for Moscow.

  • That’s a fair point, and it would had been a good idea to make diversionary attacks towards Leningrad and Moscow in any case. But, as we’ve established… They weren’t diversionary. They were the main attacks. You can equally well make the case that Germany could had tricked 50% of the Red Army to defend Moscow by diversionary attacks there, and then focusing their main forces in the South. Or, you can make the case that even if 50% of the Red Army was in the South during Fall Blau, the German army would still had beaten them if they had just… focused their efforts there.
    I personally cannot say. I see the reasoning behind this point but… There must be more effective ways of luring the enemy to divert their forces to the wrong place than to just focus all of your effort there.

  • Stalingrad was a major transport hub for oil though. The oil of the Caucasus was mostly being transported up the Volga, so taking Stalingrad would had denied the Soviets of a lot of oil. So it wasn’t just a political move to attack Stalingrad.

Hitler was not blameless, and he made mistakes all the time. He was not a strategist, and you could see it. But as it happened, he was more aware of the economic realities of Warfare than the OKH were. Though that is the lowest of low bars.

Eeeeeeeeh. Tactical weak points, not strategic ones. We must remember that the Eastern Front was enormous, and that if there was one thing Germany didn’t lack, it was places to attack. The Ukrainian front was something like 600 miles long. It wouldn’t had been a bottleneck or something. If the point is to find a weak spot in the enemy lines, strike through it, and then exploit it… Well… They would still have all the room in the world to find such a weak spot. 600 miles is a lot - The current German-Polish border is less than half that.

Hold it for dear hell until they can repair the Oil Fields and actually get their army up and running again. It would had been a uphill struggle, don’t get me wrong. Dr. Anand Toprani has made the case that after 1941, it was game over for the Germans. I think they might have stood a chance, but it would still be quite unlikely. Capturing the oil was their only hope going forward though. It would take time, a lot of time, and it would be difficult. But it was the only thing that could had saved them.

You cannot win a war if you cannot launch a large scale offensive, and you cannot launch a large scale offensive without oil. Oil was the only way Germany could win. The chance was still remote, but focusing on the Oil Fields really was the only route leading forwards. Fighting defensively is great, but no one has won a war by defending forever. As we’ve already established, a sustained war of attrition was unwinnable.

Victory could only come in the form of a large offensive, and capturing the oil fields was the only way that could happen.

Germany did launch a large scale offensive in 1943 though at Kursk and I’ve never read anything about them being short of fuel then.

Really? The Luftwaffe had to ration fuel for several months in order to be able to fight at Kursk, and they barely flew any missions in the last half of June to save fuel for the July offensive.

Compare Operation Citadel to Fall Blau, and compare Fall Blau to Barbarossa. The scale of the offensives got smaller and smaller and smaller because Germany could only support smaller and smaller operations with their fuel.

They went from this
To this
To this

It wasn’t because of lack of manpower (Germany had more soldiers in 1943 than it had had in 1942 or 1941) it was because of lack of fuel. They could only launch smaller offensives because they no longer had the fuel for the grand sweeping pushes of Barbarossa or France. Four million Axis troops participated in Barbarossa, 1.4 million in Fall Blau, and 800,000 in Citadel. Their army got larger, but their offensives got significantly smaller in both scope and amount of men involved. Because they didn’t have the fuel to launch a four million men offensive any longer, they didn’t even have the fuel for a one million man offensive any longer. Their pushes got smaller and weaker because they could only support smaller and weaker pushes with their strained Oil supplies.

At Operation Wacht am Rhein they could launch a four hundred thousand man offensive. At Spring Awakening it was three hundred thousand

It just got smaller and smaller and smaller and smaller and smaller.

By 1945, the Germans were surely limited by manpower, but before then, their army had grown and grown in size, every year, even as their offensives got smaller and smaller in scope.

Same thing goes for German tank production, it peaked in 1944

Okay, but here are some more graphs.

From https://www.quora.com/What-was-the-peak-German-strength-on-the-Eastern-Front-in-World-War-II

This is a graph showing relative strengths of the German and Soviet armies on the Eastern front. It’s not looking too great for the Germans by about 1943 and don’t forget that the Allied landings in Italy are about to kick off.

Also, while German tank production increased steadily throughout the war, so too did their losses. There’s some stuff about it here including this table.

While this includes self propelled artillery in the total AFV numbers, the key figure, tanks, peaked in 1941 and never recovered.

Finally, here is a graph of German war production including oil (source).

German oil production actually increased through to 1943. I will gladly concede that fuel was a major problem for the Germans in 1944 but I contend that was due to the Allied bombing campaign going after Ploesti and the synthetic fuel plants in a serious way.

But it just wasn’t enough, which is my point. As Dr Toprani put it
Synthetic Fuel allowed Germany to wage war but not to win it. Germany’s economically illiterate Generals scoffed at economic advisers who urged the conquest of the Caucasus by pointing out that Germany “managed to carry on the war until 1945 without ever scouring the Caucasus oil.” But at no point after the failures of 1941/42 did Germany ever possess the opportunity to win the war on favorable terms. Rather, Axis Europe had to spend the rest of the conflict laboring under constant constant shortage of energy, which constrained economic productivity and military effectiveness.”

Germany could continue on fighting defensively, and they could scrape together enough fuel to launch some small scale offensives every once in a while. But far from proving that Germany had no need of the Caucasus, Kursk proves that they had every need of it. Their offensives got smaller in scale not necessarily because they were facing more opposition but because they never had enough fuel to be able to launch an major offensive. The German Army had fought and won whilst outnumbered earlier in the war. During the initial stages of Operation Wacht am Rhein the Germans even held a numerical superiority!

The change was that Germany no longer possessed the means for large scale offensive action. it no longer possessed the means to fight a war of maneuver. They had been confined to having to pick and chose their battles carefully, rationing fuels for weeks to be able to launch an attack somewhere.

German oil production increased in 1943, but my point wasn’t that German fuel production decreased, it was that there was not enough oil.

In 1939, 1940, and the first half of 1941, they could get away with that production because they could import from the Soviet Union and they had their own stockpile. But as the stockpile was depleted and the imports were gone, Germany, even though she domestically increased her production by 500,000 tonnes between 1939 and 1943, couldn’t replace the 900,000 tonnes of Imported Soviet Oil that they no longer had access to.

Even when they had been receiving almost a million tonnes by the Soviets, they still only had 18% of their peacetime shipments, and even those peacetime shipments were far too little! When that was gone, the Germans had nowhere near enough fuel.

Capturing the Caucasus was the only way to change that, and the only way to solve this problem. It was the only way Germany could receive the oil she needed, the only way she could launch future offensives on any significant scale, and the only way she could possibly win the war.

We must remember that the pre-war oil situation was not good enough, and that simply returning to that or even surpassing it wouldn’t be enough. Realistically speaking, the only way Germany could receive the fuel it needed was by capturing the Caucasus.

The source you gave for your final graph is wonderful. The Author more or less makes the exact same point I’m making

“If I had to change one thing, and one thing only, to help Nazi Germany win World War 2, I would not go for “smarter Hitler” or “better strategies” and certainly not “more Tigers and Panthers”. My money would be on “an always-full tank of gas”.”

“As the war went on, the fuel situation of the German deteriorated sharply.”

Germany’s fuel situation didn’t get better in 1943, it got worse. Even if it did get better in the short-term (As in “We have more fuel now than we had a year ago”) in the long-term, it was just a drop in the bucket of what they needed.

Synthetic Fuel was, as Dr Toprani argued, not enough. Germany needed the Caucasus oil fields to get the fuel they needed. With all likelihood, Germany would had still lost the war even if they had captured the Caucasus simply because of how thoroughly the Soviets destroyed the Oil Fields, but it was Germany’s only hope.

1936, 1939, 1943. It doesn’t matter. At none of these dates did Germany produce enough fuel to sustain it’s economy and it’s army fully. They were always rationing and prioritizing. Even during the best of circumstances, when their own Domestic Production was at it’s highest, they were still rationing and prioritizing.

First of all, thank you Jen for a most interesting and stimulating debate.

I kind of agree with the point you’re trying to make but I don’t think the Wehrmacht was in any shape to launch another campaign on the scale of Barbarossa or even Case Blue, even if it had limitless amounts of fuel.

More fuel won’t help II SS Panzer Corps break through at Prokhorovka, for example, or the 6th Army to hold Stalingrad. More fuel won’t stop the Allies landing in Italy or France nor will it stop the Red Army steamrollering Army Group Centre in the summer of 1944.

More fuel might help Kleist get to Baku or Rommel to break through at Alamein, ironically, but there is still the transport problem to solve, namely how to get the fuel to the front and also how to refine it and ship it back to Germany.

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Thank you too!

And well… That’s true, but we must also ask yourselves, how many offensives and operations didn’t happen because of the lack of fuel? Having more fuel wouldn’t had helped at Citadel or at the various Allied invasions, but, having more fuel meant that Germany might not have found themselves in that situation to begin it. They didn’t run into the issue of running out of fuel at Kursk, but that was only because Kursk was so much smaller when compared to other operations.

I would still contend that the impact of oil was very significant, because even if it didn’t directly impact the operations that did end up happening, if they hadn’t run short of oil, they could had planned larger and better operations to begin with because they had the fuel for it.

With the issue of transport. Yeah. Oil certainly wasn’t the only thing that caused Germany’s defeat, but it is, IMHO, the biggest thing. For transport… If the Wehrmacht had had enough fuel, then they wouldn’t had needed to demotorize the army as much as they did, and the Italian Navy would had had enough fuel to be able to transport fuel to Rommel, which was a significant issue in real life.

Furthermore, with enough fuel to run their ships, the Italian Navy could had actually started to harass the British Convoys moving through the Mediterranean, which would had been a massive relief for Rommel.

That’s sort of my view: At the surface, it might appear that oil didn’t play a big impact directly, but indirectly, having enough oil would had been massive for Germany. If they had enough oil, they would had had the options and flexibility to do things that in real life they had to cancel.

I think we can both agree that by 1943/44, it was too late for Germany. There was no coming back at that point. Operation Bagration and Operation Overlord were a coup de grâce more than anything else.

So the question arises, did Germany ever have a chance to win the war?

In my opinion, I find it hard to imagine a scenario where Germany wins the war. But it’s straight up impossible for me to imagine a scenario where they win the war without Caucasian oil.

I think that Toprani’s quote really underlines the difference perfectly
“Synthetic Fuel allowed Germany to wage war but not to win it."

Let’s take this in another direction then. If Barbarossa was doomed to failure, is there another way that Germany could have won the war?

Guderian claimed in his book Panzer Leader that he thought that Germany should forgo invading Russia and send at least 6 Panzer divisions to North Africa to crush the Western Desert Force, take the Middle Eastern oil fields and force Britain to negotiate. This may be difficult given the supply problems Rommel had historically with only 2 panzer divisions and one light division. A successful advance on Alexandria though would force the Royal Navy to abandon the Eastern Mediterranean and give the Axis a large port, greatly simplifying their logistics and would probably allow the Axis to push on into the Middle East.

The other possibility would be to find a way of compelling Britain to surrender in 1940. This isn’t at all impossible as there was a great deal of political pressure in Britain to negotiate with the Germans following the defeat in France. Had the BEF been lost at Dunkirk, for example, then carrying on with the war would be be very difficult.

With Britain out of the war then there is no blockade and Germany is able to trade with the rest of the world. Some of the occupied countries in Europe have significant resources in their colonies, the Dutch East Indies’ oil fields springing to mind immediately, which Germany would have had access to on extremely favorable terms.

This also fails on oil. Guderian is again being optimistic about the possibilities. To do this, the very least the Germans need are the oil fields in Eastern Galcia, which before 1939 were in Eastern Poland on the border to Ukrainian USSR. With the German Soviet pact these oil reserves have now gone mostly to Russia.

That was never in the cards, especially not the moment that Churchill replaces Chamberlain. Obliterating the BEF at Dunkirk is a tendentious possibility at best. It wasn’t a mistake that the Germans halted their advance before reaching the city.

While moving and pressing the Anglo-French forces back the British Forces and the French forces were spread along a thinner line. The Germans could strike and break through in several places, which they did.

Once the BEF is concentrated in Dunkirk, together with the French forces that managed to join them, the Wehrmacht is facing a thick and deep defensive position. They don’t have the power to completely cut off a resupply line from Britain (as the evacuation showed). What follows is a drawn out siege, this leaves the rest of the Wehrmacht incapable of securing France and withstanding resistance.

Yep. A couple of factors may mitigate that though. 6 panzer divisions is about the equivalent of 1 panzergruppe in Barbarossa so our newly beefed up Afrika Corps is going to need less stuff than, say, invading the Soviet Union. If the Luftwaffe can be persuaded to go all out on Malta and land a decent force of fallschirmjager there then that makes the supplying of Axis forces a bit easier. I genuinely don’t know if the shipping capacity exists to transport and supply 6 panzer divisions in North Africa though, even assuming the Germans have the stuff to send to them.

Taking Egypt also doesn’t automatically get them the Middle East either. Britain sent some very substantial reinforcements which historically were used for Crusader/Battleaxe. At least some of those could presumably find their way to Iraq via Basra although I’m not sure how well developed that was as a port at the time.

Well Britain is a democracy and it is possible that with the BEF gone Churchill could face a vote of no confidence and be replaced with somebody like Halifax. He came very close IRL and a heavy defeat in France could be the straw that broke the camel’s back. If Hitler offered generous terms, it might be a possibility.

You are absolutely correct though about Dunkirk being a tough nut to crack for the Wehrmacht if they were to try a direct assault. Another factor to consider is that, rather like Barbarossa a year later, the panzer and motorized units are worn out and need to refit/repair while a lot of the infantry is still marching hard to catch up. Goering’s promise that the Luftwaffe could wipe out the beachhead by itself must have seemed very attractive.

There’s another gigantic elephant in the room to consider as well, although it’s unlikely that German planners were aware of it at the time.

Any attempt by the Germans will remain a hail Mary pass at best. Also don’t forget Japan in all of this. For Japan, attacking the US is must as they need their pacific islands to continue expanding. The moment they do US is in the war. Germany might be able to delay an entry of the US to the European theatre, by not declaring war on the US, but sooner or later they will and again at that point everything is lost due to the economic maths.

I remain with my analysis in the article, there is no military scenario that will mitigate the economy enough to make for a possible German victory, it just doesn’t add up.

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The entire German war effort was a Hail Mary play when you get right down to it. The only way they win is if at least one of Britain or the USSR gives up and they never found a way to force them to do that. Germany couldn’t successfully invade Britain and it couldn’t conquer the entire USSR. While at times they may have come close, ultimately they were doomed to failure.

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The British Blockade on Germany was definitely one of the most important factors of the war, and if it would had been possible for Germany to avoid it, then their chances of victory would had been far greater. But unfortunately for Hitler, the United Kingdom is defended by the Greatest trench ever built; The English Channel, and objectively looking at it… It’s almost impossible to imagine a situation where Germany successfully managed to knock Britain out of the war.

As long as the Royal Navy was still afloat, the United Kingdom was more or less impervious to any German invasion, and without the serious threat of a German invasion, the UK had very little reason to seriously fear an invasion.

In North Africa… As you alluded to, I doubt that sending more divisions would had ended up positively impacting the DAK’s performance. The Italians couldn’t even supply the initial two German divisions in Norh Africa even before Rommel went on the offensive. Adding more divisions might have made the Germans perform better, but I suspect that if the OKH sent 7 divisions, they would had all ended up collecting sand in the desert because there was no fuel to run them with.

It’s a bit of a paradoxical Catch-22: Germany needed oil to be able to win battles, but needed to win battles to get that oil.

I would echo Spartacus in the conclusion that

I suppose that if we really tried, we could probably think of some insane scenario where Germany managed to lure the Royal Navy into a trap and beat them and them with some magical invention invade the UK, but at that point, we’re just turning into the History Channel with conjectural alternate history.

Germany, indeed, was just throwing Hail Mary’s, it was their entire strategy. They went all in over and over and over, gambled everything on chance, it was bound to fail sooner or later.
During the Polish campaign, they gambled everything on that the French wouldn’t seriously pursue the Saar offensive. During the French campaign, they gambled everything on the Ardennes push. During Operation Barbarossa, they gambled everything on success within 2-3 months.

And just like with any gambler - Sooner or later, you lose everything.