Could a German invasion of Turkey succeed?

[Avalancheon]

Lets assume a scenario where the Nazi-Soviet talks in November 1940 hadn't ended in such dismal failure (leading Hitler to believe that Stalin was planning to betray him). Since they are still satisfied with their diplomatic relations, Germany does not embark on a plan to invade the USSR. Instead, they decide to attack into the middle east and dislodge the British from that region.

They send diplomats in an attempt to convince Turkey to join the Axis, or at least to allow German forces passage through their territory. These talks go nowhere, and nothing comes of it. Hitler orders the general staff to prepare an invasion plan. After the campaign in Yugoslavia and Greece is wrapped up in April 1941, the Germans position troops on the Turkish border and issue their demands: Stand down, or be conquered.

The government refuses to negotiate, and the Wehrmacht is ordered into action. Panzer divisions quickly overrun eastern Thrace and capture large numbers of enemy troops. They advance all the way to the Bosphorous straits, crossing it and capturing the capital. The country is in panic and civilians flee from Istanbul. By this point, however, the Germans are facing an advance into much tougher terrain that is defended by the bulk of the Turkish army.

After that, what would the next step for the Wehrmacht be? Would they try to send their divisions along the plateaus, ridges, and mountains of the interior? Or would they stage amphibious landings along the coastline?


Turkey did not have a very good railway coverage even by the standards of 1941. Exact figures on the extent of their lines at that time is hard to come by. However, according to one report: ''The length of railway line in Turkey in May, 1931, was 3619 miles broad gauge and 359 kilometres (225 miles) narrow gauge.''

Another problem facing the Germans was that many of these lines were only single track, which did not allow trains to run in opposite directions at the same time. That means the freight capacity of the line was lower. Would this infrastructure be sufficient to enable them to advance through Turkey at a rapid rate? Or would they be forced to move at a more timorous pace and upgrade the capacity of the lines as they went?

[xristar]

After the campaign in Yugoslavia and Greece is wrapped up in April 1941, the Germans position troops on the Turkish border and issue their demands: Stand down, or be conquered.

The government refuses to negotiate, and the Wehrmacht is ordered into action.

The Turkish army in April 1941 was fully mobilized and its bulk was deployed defensively in Eastern Thrace. The Wehrmacht in the Balkans was stretched out and also limited by the Balkan logistical network. An attack on Turkey immediately after the conquest of Yugoslavia and Greece cannot take place, and even if we assume that Germany had already made the necessary preparations beforehand (given that there would be no Barbarossa), one thing is certain: the Turks would be -within their limited means- fully warned and prepared. The campaign in Eastern Thrace for the Germans would be very different than the attack on Poland, on Yugoslavia and on the USSR.

Panzer divisions quickly overrun eastern Thrace and capture large numbers of enemy troops. They advance all the way to the Bosphorous straits, crossing it and capturing the capital.

Undoubtedly the Germans would easily overrun the plains of Eastern Thrace. But the Turks, like they had done in the past, would certainly have prepared defences at the chokepoint to Istanbul ie the Chataltza line. Artillery positions, anti-tank obstacles and moats, minefields, trenches etc. Moreover, even with their limitations in equipment, they could still deploy hundreds of thousands of infantry, a couple of thousands field artillery and hundreds of AT guns. It would be a bloody assault into a very dense defensive position.
Thus I do not see an easy conquest of Istanbul for the Germans.

The Bosporus is on average about 1.5km (~1 mile) wide. Crossing it against opposition is easier said than done.

The capital is Ankara. I assume you made a mistake and thought Istanbul was the capital. Otherwise I do not see how, after crossing the Bosporus, the Germans would leisurely drive unopposed the 450km (~300 miles) to Ankara.

[Carl Schwamberger]

Its not clear what the strategic goal is here. That is a factor in judging success. A general statement of flanking the Middle east is a bit to vague. When the Germans had strategic or operational success they also had clear priorities and clear identified the main effort, and the alternatives. In this case are the oil fields near Mosul the next objective, or is it the Levantine littoral-leading to Egypt?

[Futurist]

Its not clear what the strategic goal is here. That is a factor in judging success. A general statement of flanking the Middle east is a bit to vague. When the Germans had strategic or operational success they also had clear priorities and clear identified the main effort, and the alternatives. In this case are the oil fields near Mosul the next objective, or is it the Levantine littoral-leading to Egypt?

What would the results be for either of these two priorities?

[Avalancheon]

The Turkish army in April 1941 was fully mobilized and its bulk was deployed defensively in Eastern Thrace. The Wehrmacht in the Balkans was stretched out and also limited by the Balkan logistical network.

According to Brock Millman, the Turkish army underwent a massive and rapid expansion when war broke out. They had 300,000 men in 1939, but the following year, they had inflated to 1.3 million men. There is no way they could have adequately trained that many soldiers in that little time. Nor could they have raised enough officers and NCOs to lead them all. An extra year of time (1940 to 1941) wouldn't have changed this very much.

And thats ignoring all the equipment shortages the Turks would have had. Not only would there not be enough small arms to equip all those men*, there wouldn't be nearly enough anti-tank guns or artillery, to say nothing of motor vehicles and communications equipment. Brock Millman seems to confirm these problems, saying that many of the new draftees were being used as porters and laborers, rather than soldiers.

*As late as February 1940, the British Foreign Office noted: "The Turkish Army is very short of rifles and has asked us to supply 150,000."

The Turkish army in April 1941 was fully mobilized and its bulk was deployed defensively in Eastern Thrace. The Wehrmacht in the Balkans was stretched out and also limited by the Balkan logistical network. An attack on Turkey immediately after the conquest of Yugoslavia and Greece cannot take place, and even if we assume that Germany had already made the necessary preparations beforehand (given that there would be no Barbarossa), one thing is certain: the Turks would be -within their limited means- fully warned and prepared. The campaign in Eastern Thrace for the Germans would be very different than the attack on Poland, on Yugoslavia and on the USSR.

The Wehrmacht would need to consolidate their gains after the Balkans campaign (before they moved on to Turkey), so the invasion wouldn't happen until mid-May at the earliest. Bulgarias railway network was well connected to Romania and Serbia, but not to Greece. The infrastructure should be able to support a German push into Turkey, without creating bottlenecks. Likewise, the railways in Thrace are enough to satisfy the Wehrmachts needs. The only question is whether the infrastructure would enable them to continue pushing deep into the country at a decent pace.

Undoubtedly the Germans would easily overrun the plains of Eastern Thrace. But the Turks, like they had done in the past, would certainly have prepared defences at the chokepoint to Istanbul ie the Chataltza line. Artillery positions, anti-tank obstacles and moats, minefields, trenches etc. Moreover, even with their limitations in equipment, they could still deploy hundreds of thousands of infantry, a couple of thousands field artillery and hundreds of AT guns. It would be a bloody assault into a very dense defensive position.
Thus I do not see an easy conquest of Istanbul for the Germans.

And in conquering eastern Thrace, the Wehrmacht would destroy the bulk of Turkeys forces that existed before the war, the best trained and equipped men in the army. That would leave mainly the forces that had been mobilized after the war broke out. The dregs of their military, in other words. Large in number, but low on skill.

But about the Chataltza line. Do you know for certain how many anti-tank weapons and artillery pieces the Turks had at their disposal? Would they really be willing to send the bulk of their arsenal there, knowing it would be lost when the Germans inevitably broke through?

The Bosporus is on average about 1.5km (~1 mile) wide. Crossing it against opposition is easier said than done.

The capital is Ankara. I assume you made a mistake and thought Istanbul was the capital. Otherwise I do not see how, after crossing the Bosporus, the Germans would leisurely drive unopposed the 450km (~300 miles) to Ankara.

This narrow frontage works both ways, however. While it greatly limits the Germans ability to move around, it would also enable them to concentrate a massive amount of artillery and pulverise anything on the other side of the Bosphorous strait. Do you remember those pictures of the Red Army later in the war, when they had so many artillery pieces that they literally had them lined up wheel-to-wheel? Thats what the Germans would be doing.

The narrowness of the Bosphorous straits also limits the Turks ability to disperse. They will be quite vulnerable to massed artillery barrages, even if they dig in. And then there is the fact that the Luftwaffe will have complete air supremacy, and will be able to maintain a continuous presence over the straits. So they will be exposed to attack 24\7, and will be literally buried under a carpet of bombs. The Turkish armys only hope to put up even a token fight will be to extensively fortify the area.

[Avalancheon]

Its not clear what the strategic goal is here. That is a factor in judging success. A general statement of flanking the Middle east is a bit to vague. When the Germans had strategic or operational success they also had clear priorities and clear identified the main effort, and the alternatives. In this case are the oil fields near Mosul the next objective, or is it the Levantine littoral-leading to Egypt?

Logistically, the easiest route would be through Syria and into Transjordan, so thats probably the path the Germans would choose. In combination with a renewed assault from the Afrika corps, it would enable them to pincer the British forces in Egypt.

What would the results be for either of these two priorities?

If the Germans push south, that would enable them to secure the Mediterranean coastline, taking Syria and Transjordan, and eventually Egypt itself. That would be a devastating geostrategic setback for the British. However, they would still have control of oil rich Iraq. This would be their last stronghold in the near east and would be defended to the bitter end.

However, if the Germans push east, that would enable them to take Iraq and prevent the revolt from being put down. This is logistically the harder route to go, but it would give them access to large oil fields. The Iranians would also be emboldened by their presence, and would probably join the Axis. Having their oil supply cut off would hurt the British alot, but they would maintain a very strong presence in Egypt.

So there are different payoffs and compromises with either plan.

[pugsville]

Logistically, the easiest route would be through Syria and into Transjordan, so thats probably the path the Germans would choose. In combination with a renewed assault from the Afrika corps, it would enable them to pincer the British forces in Egypt.

Not that easy. The Turkish train lines are really poor. And without any trains trucking stuff across turkey to syria would have much teh same diffacultiues in supporting an offensive against Egypt from Tripoli,

If the Germans push south, that would enable them to secure the Mediterranean coastline, taking Syria and Transjordan, and eventually Egypt itself. That would be a devastating geostrategic setback for the British. However, they would still have control of oil rich Iraq. This would be their last stronghold in the near east and would be defended to the bitter end.

However, if the Germans push east, that would enable them to take Iraq and prevent the revolt from being put down. This is logistically the harder route to go, but it would give them access to large oil fields. The Iranians would also be emboldened by their presence, and would probably join the Axis. Having their oil supply cut off would hurt the British alot, but they would maintain a very strong presence in Egypt.

So there are different payoffs and compromises with either plan.

Any German invasion of Turkey would be opposed by British forces, there was a fair bit of co-operation, British supplying equipment , training aircrew in England. A couple of British divisions some Turkish forces could hold up the Germans in Eastern Turkey (Cilcain gates Tarsus mountains for instance) , where the Germans at the end of another long truck convoy system struggle to supply enough supplies to the front in terrain much less suitable for mobile tank warfare,.

[thaddeus_c]

Its not clear what the strategic goal is here. That is a factor in judging success. A general statement of flanking the Middle east is a bit to vague. When the Germans had strategic or operational success they also had clear priorities and clear identified the main effort, and the alternatives. In this case are the oil fields near Mosul the next objective, or is it the Levantine littoral-leading to Egypt?

possibly apply the same treatment dealt to Slovakia (Slovak Republic) and Romania?

under this scenario of continued cooperation with USSR they might capture some parts of the country, such as Kars in the east and Hatay on border with Syria, while holding out, perhaps, Mosul being returned to them?

[Avalancheon]

Hi everyone, thanks for the responses. I've already posited what I think will happen in the initial stages of the invasion, so now I would like to go into more detail about that and explain my reasoning.

Based on their performance in the Balkans and the Soviet Union, I think the Germans should be able to take eastern Thrace in about a week. And maybe a week after that, they can establish a foothold on the opposite banks of the Bosphorous and Dardanelles. This would undoubtedly come as a shock to the British, given their failure to take Gallipoli in WW1 (and their belief that no other army could have done any better). If the Germans invade in the middle of May, which is about the earliest date possible given OTL events, then they should be ready to launch attacks into the heart of Turkey by early June.

As for what kindof forces the Wehrmacht would have assembled for their campaign. I think that the invasion would be spearheaded by a large panzer group composed of 6 panzer divisions and 5 motor infantry divisions. They would probably be backed up by two smaller infantry armys, each composed of 8-9 infantry divisions. These would all be first rate, elite forces, the best in the German army. As they move deeper into Turkey, they would probably be reinforced with mountain divisions. Let me know if anyone disagrees with this assessment.

Looking at the railway map of southern Europe, it looks like there is some decent infrastructure in Hungary, Romania, and Bulgaria itself (which the Wehrmacht would use as its launching pad). Hence, I don't think there would be any major issues moving troops and supplies from Germany to Bulgaria. The problems will come only when they move into eastern Thrace itself, as there is only one major railway line supplying that area. Things only improve once you get into mainland Turkey itself.




I've talked to our resident expert on railways, Der Alte Fritz, and he thinks the Wehrmacht could potentially go as far as 600 km before their logistics break down. Thats roughly the distance from the borders to Ankara. So the Germans should be able to seize the capital, with a bit of luck. I have no idea what they'll be able to do from that point onward, though. If they stop their advance for an operational pause and can move their supply districts closer to the front lines, they should be able to resume the advance. If the Wehrmacht is unable to move their supply districts forward, they are kindof stuck. So the question is, what do the Turks do after the fall of Ankara? Do they surrender, or continue fighting?

If they choose to fight on, then I think the Germans would be limited mainly to slow advances along the railways. The geography becomes steadily more mountainous the further east you go, so their avenues of approach are limited and predictable. Even the poorly trained, demoralised remnants of the Turkish army should be able to turn their advance into a slog by this point. They can stage constant ambushs along these mountain paths and slow the German advance to a crawl, while inflicting increasingly heavier casualties.


WRT the railways, there is an issue that I mentioned only in passing. That is the fact that Turkish railways are of broad gauge, which means they are incompatible with German locomotives and rolling stock. Thus, they will have to be converted by railway engineers to conform to standard gauge. This is the same problem that confronted the Wehrmacht in the Soviet Union. Fortunately, they still have a large number of railway construction battalions that can be used for this task.

Moreover, the length of railway lines they have to convert is much smaller than what they did in operation Barbarossa. For reference, the Germans captured 25,700 kms of Russian railways and converted much of that to standard gauge. Turkey probably has under 7000 km of railways, so this makes the magnitude of the challenge much more manageable. Although to be fair, some extra lines would have to be built to overcome local bottlenecks and shortages in freight capacity.

[Avalancheon]

Not that easy. The Turkish train lines are really poor. And without any trains trucking stuff across Turkey to Syria would have much teh same diffacultiues in supporting an offensive against Egypt from Tripoli,

The strike into the south isn't as logistically challenging as you think. The railway infrastructure in south-east Turkey links directly to Aleppo, after all. You should refer back to the railway map provided in the OP. Theres also the possibility of using sea lift along the coast for resupply.

Out of curiosity, why do you think the Germans wouldn't have any trains to supply them, if they got far enough to mount an invasion into Syria itself? Thats a rather strange thing to say. If they didn't have the use of the railways, the Nazis wouldn't have gotten that far to begin with!

But anyway, the discussion is too young to come to any conclusions on this part of the campaign... We're still trying to figure out whether Turkey could continue resisting after the fall of Istanbul and Ankara. But on the off chance that they do surrender (which isn't exactly a given), then that would give German trains free access to travel across the entire length of the country. FYI.

Any German invasion of Turkey would be opposed by British forces, there was a fair bit of co-operation, British supplying equipment , training aircrew in England. A couple of British divisions some Turkish forces could hold up the Germans in Eastern Turkey (Cilcain gates Tarsus mountains for instance) , where the Germans at the end of another long truck convoy system struggle to supply enough supplies to the front in terrain much less suitable for mobile tank warfare,.

Yes, but theres not exactly a hell of a lot the British can do in this situation. In their shameful retreat from Greece, they threw away the islands of Lemnos and Samothrace. They have no way to safely bring in troops or supplys by sea through the Dardanelles. Their ships would be bombed by the Luftwaffe and hunted by the Regia Marina. Instead, the Navy will be limited to using ports that are further away along the coast. Izmir is about as close as they can reasonably get, before their precious ships get threatened by aircraft, ships, and submarines.

The British have no ability to help Turkey in any appreciable way during the early stages of the invasion. There is nothing they can do to stop the fall of eastern Thrace. However, they can help make the German advance into the mainland more difficult than it would otherwise be. Like you say, the Cilician passes and Tarsus mountains are very defensible terrain. The British could probably stop them cold in that area.

possibly apply the same treatment dealt to Slovakia (Slovak Republic) and Romania?

under this scenario of continued cooperation with USSR they might capture some parts of the country, such as Kars in the east and Hatay on border with Syria, while holding out, perhaps, Mosul being returned to them?

Good point. During the Nazi-Soviet talks in November 1940, the Germans were actually willing to partition Turkey between them, and make revisions to the Montreux convention. (This was a treaty that prevented the USSR from having unrestricted access to the Bosphorous and Dardanelles)

If Molotov (and by extension, his boss) hadn't been so greedy and unreasonable at the conference, this actually might have ended up happening. Theres lots of ramifications from this. Among other things, it would solve the perennial Russian problem of having limited access to the oceans.

[thaddeus_c]

possibly apply the same treatment dealt to Slovakia (Slovak Republic) and Romania?

under this scenario of continued cooperation with USSR they might capture some parts of the country, such as Kars in the east and Hatay on border with Syria, while holding out, perhaps, Mosul being returned to them?

Good point. During the Nazi-Soviet talks in November 1940, the Germans were actually willing to partition Turkey between them, and make revisions to the Montreux convention. (This was a treaty that prevented the USSR from having unrestricted access to the Bosphorous and Dardanelles)

If Molotov (and by extension, his boss) hadn't been so greedy and unreasonable at the conference, this actually might have ended up happening. Theres lots of ramifications from this. Among other things, it would solve the perennial Russian problem of having limited access to the oceans.

from the German perspective it would be better to have the Soviets lumber into a conflict with Turkey and/or Iran than swallow up Finland and the Baltics? (their little pre-war trading bloc)

the Nazi regime might find some fellow travelers among the Syrian Nationalists, under this scenario there is no (immediate) invasion of USSR so the Med and Middle East would be primary target. from Syria they could agitate renewed Palestinian uprisings against the British and reclaim Hatay under threat of larger invasion.

if Kars and Hatay taken, nearly surrounded, they (Turkey) might be more agreeable over access thru Turkish Straits, without need to attack directly into bulk of Turkish army?

[TheMarcksPlan]

Bumping this because subject has come up in another thread.viewtopic.php?f=11&t=251596#p2289483

I've talked to our resident expert on railways, Der Alte Fritz, and he thinks the Wehrmacht could potentially go as far as 600 km before their logistics break down.

I assume he means truck logistics would break down? In Barbarossa it was 300km max in planning and in experience. Here there's maybe 20% of the divisions so doubling the truck-based logistical reach seems a bit conservative.

If they choose to fight on, then I think the Germans would be limited mainly to slow advances along the railways.

In Barbarossa they regauged the rail lines at >20km/day across a huge front. If they committed the same railroad troops to Turkey they'd almost certainly re-gauge faster along only 2-3 lines at once. 20km/day gets you from Izmir to Ankara in a month even after all the bends in the road. https://www.google.com/maps/dir/Ankara, ... d38.423734 Call it two months, still a short war.

Granted the re-building in Barbarossa was cheaply done, limiting Ostheer's supplies. With 20-30 divisions instead of >150, however, even a cheap/quick rail rebuild should be fine.

Izmir is about as close as [the British] can reasonably get, before their precious ships get threatened by aircraft, ships, and submarines.

I find it inconceivable that the British would send naval vessels, let alone slow troop transports, anywhere in the Aegean amidst a LW/KM/RM buildup for a Turkish invasion. Approaching Izmir requires 300nm exposure to concentrated air/naval power without any air cover in range (unless RN risks all its carriers and even then they'd be overwhelmed). Any heavy British units could be lost to KM/RM torpedo boats alone - and the Italian boat crews were really aggressive.

To access Izmir the British would have to take Crete and/or Rhodes, set up airfields, then hop northwards. As a practical matter, it'd all be over long before that, even if Britain scrapes together the forces to hold the Tarsus line.

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

I appreciate your calling this discussion "young" upthread - I'm only beginning to form thoughts on how this would go. IMO this discussion has so far ignored Axis control of the Aegean and its implications for the invasion. As discussed in the linked post, the Aegean and RM/KM/LW control over it makes at least Western Anatolia indefensible.

Once the Axis has taken Thrace and Western Anatolia, can take several routes to emerge onto the Anatolian Plateau, after which there's no secure geographic line until the Tarsus Mountains (Anatolia is not that mountainous). Getting only halfway there removes all of Turkey's small industrial base, most of her population/agriculture, etc. At that point it's an Axis-Wallies theater regardless of whether Turkey continues fighting de jure.

Unless we're talking 1944 or later, the W.Allies can slow Germany but can't stop it: shipping the Torch forces ~4,000 miles from US and ~2,000 from UK took so much shipping it reversed the Bolero buildup. Shipping the Torch forces round the Cape to MidEast would probably require ending all Pacific offensives. If the 50 or so free divisions required to hold a determined Heer somewhere in Eastern Anatolia actually existed, shipping/supplying them would require the British economy massively to cut back imports.

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During the Nazi-Soviet talks in November 1940, the Germans were actually willing to partition Turkey between them, and make revisions to the Montreux convention. (This was a treaty that prevented the USSR from having unrestricted access to the Bosphorous and Dardanelles)

If Molotov (and by extension, his boss) hadn't been so greedy and unreasonable at the conference, this actually might have ended up happening. Theres lots of ramifications from this. Among other things, it would solve the perennial Russian problem of having limited access to the oceans.

You're referring to Soviet demands for influence/guarantees re Yugoslavia and Bulgaria? And probably other issues. If Hitler hadn't just ignored the post-conference inquiries about a settlement, German presence in those countries would have been a fait accompli. Stalin would probably have been happy to get bases on the Straits, return of Kars province, plus reciprocal guarantees/neutrality for Bulgaria.

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

EDIT - I forgot that the OP specifies a mid-'41 timeline. Anything inconsistent with that can be ignored (too lazy to change everything).

IMO Germany wouldn't have done this as quickly as the OP implies (May '41?). Even when planning for a quick campaign like Barbarossa, Hitler/OKH/OKW made sure their ducks were in row: the massive rail investment program up to the Polish border, the belated crash armaments program for Barbarossa, etc. Germany/Axis (inc. Bulgaria for Adrianople?) would have paused a few months, probably asked for passage to the real objectives (Syria and beyond), then invaded from well-prepared footing on Thracian and Aegean fronts.

[TheMarcksPlan]

If the 50 or so free divisions required to hold a determined Heer somewhere in Eastern Anatolia actually existed, shipping/supplying them would require the British economy massively to cut back imports.

Because one of my pet peeves on this site is for folks to say "but logistics!" without providing a scintilla of data on actual logistics, here's some data:

From page 825 of Global Logistics and Strategy volume 2, an ETO solider required 66.8 lbs/day maintenance. (I'm looking only at supplying an army in Turkey, not moving one there)

In-theater division slice for the U.S. Army was >30k but let's say 30k.

50 divisions is 1.5mil men.

That force requires 45k long tons per day; 1.35mil per month, 16mil per year.

British imports ran at mid-20's million long tons per year. The sea route from New York to Basra or Suez is ~4x longer than to Britain.

So it would take more shipping to supply an active 50-division front in the MidEast than was required to supply all of Britain.

Initial shipping requirements are harder - not impossible - to estimate but would be on the order of the monthly maintenance requirement.

The British were a little less extravagant than US in supplying their forces but not sufficiently different to make large-scale Anatolian ground warfare remotely feasible. (btw - is there a British tome analogous to Global Logistics and Strategy?)

[Avalancheon]

I assume he means truck logistics would break down? In Barbarossa it was 300km max in planning and in experience. Here there's maybe 20% of the divisions so doubling the truck-based logistical reach seems a bit conservative.

This is what Der Alte Fritz told me, in essence: The Germans will build up supply depots for an extended period of time, and then use them to sustain an advance to a depth of up to 600 km. Railway capacity is not a limiting factor under these circumstances. But after an advance of 600 km (or a campaign lasting over three months), the depots will be used up and the Wehrmacht must come to an operational halt.

In Barbarossa they regauged the rail lines at >20km/day across a huge front. If they committed the same railroad troops to Turkey they'd almost certainly re-gauge faster along only 2-3 lines at once. 20km/day gets you from Izmir to Ankara in a month even after all the bends in the road. https://www.google.com/maps/dir/Ankara, ... d38.423734 Call it two months, still a short war.

Exactly. This campaign is well within their means to pull off. In terms of scale, intensity, and duration, it won't be much different from the invasion of Yugoslavia and Greece.

I find it inconceivable that the British would send naval vessels, let alone slow troop transports, anywhere in the Aegean amidst a LW/KM/RM buildup for a Turkish invasion. Approaching Izmir requires 300nm exposure to concentrated air/naval power without any air cover in range (unless RN risks all its carriers and even then they'd be overwhelmed). Any heavy British units could be lost to KM/RM torpedo boats alone - and the Italian boat crews were really aggressive.

Right. I was just trying to point out the obvious difficultys that would face the British if they attempted to deploy troops to Turkey by sea. It would be suicide for the ships involved. They would have to come by land instead.

I appreciate your calling this discussion "young" upthread - I'm only beginning to form thoughts on how this would go. IMO this discussion has so far ignored Axis control of the Aegean and its implications for the invasion. As discussed in the linked post, the Aegean and RM/KM/LW control over it makes at least Western Anatolia indefensible.

Once the Axis has taken Thrace and Western Anatolia, can take several routes to emerge onto the Anatolian Plateau, after which there's no secure geographic line until the Tarsus Mountains (Anatolia is not that mountainous). Getting only halfway there removes all of Turkey's small industrial base, most of her population/agriculture, etc. At that point it's an Axis-Wallies theater regardless of whether Turkey continues fighting de jure.

Agreed. Even if the Turks refuse to capitulate after the fall of Istanbul and Ankara, their ability to resist will be negligible. By that point, they will be waging a large scale guerilla war only.

You're referring to Soviet demands for influence/guarantees re Yugoslavia and Bulgaria? And probably other issues. If Hitler hadn't just ignored the post-conference inquiries about a settlement, German presence in those countries would have been a fait accompli. Stalin would probably have been happy to get bases on the Straits, return of Kars province, plus reciprocal guarantees/neutrality for Bulgaria.

Yes, I was referencing that. The Soviet proposals that came after the November 1940 conference were somewhat generous to the Germans. They were also very expansive in scope, and would resolve most of their disputes.

One point of friction was the desire of the Soviets to sign a pact with Bulgaria. This could potentially interfere with the German military buildup for operation Marita.

EDIT - I forgot that the OP specifies a mid-'41 timeline. Anything inconsistent with that can be ignored (too lazy to change everything).

IMO Germany wouldn't have done this as quickly as the OP implies (May '41?). Even when planning for a quick campaign like Barbarossa, Hitler/OKH/OKW made sure their ducks were in row: the massive rail investment program up to the Polish border, the belated crash armaments program for Barbarossa, etc. Germany/Axis (inc. Bulgaria for Adrianople?) would have paused a few months, probably asked for passage to the real objectives (Syria and beyond), then invaded from well-prepared footing on Thracian and Aegean fronts.

Well, it depends on how soon they can get Bulgaria to join the Axis. This didn't happen until March 1, 1941 in OTL. The Germans weren't able to deploy troops to Bulgaria before then. If it happens earlier, then they can begin their buildup for operation Marita earlier (and then for an invasion of Turkey). I was a bit hasty in speculating about a May 1941 start date.

[TheMarcksPlan]

Well, it depends on how soon they can get Bulgaria to join the Axis. This didn't happen until March 1, 1941 in OTL. The Germans weren't able to deploy troops to Bulgaria before then.

To my surprise while reading a few months back, Bulgaria gave permission in December. Hitler appears to have slow-walked Marita for better weather, assuming that a delayed Barbarossa still allowed plenty of time to push over the Soviets before winter. Source is Hitler's Balkan Campaign and the Invasion of the USSR by Zapantis.

Not as deeply read on the issue but AFAICS Hitler/Ribbentrop delayed announcement of the minor Tripartite Pact signatories until March because they were wrangling with Yugoslavia, Turkey, Hungary etc.

A big element needing explication in my Barbarossa ATL's is what if Hitler launches Marita in the winter and Barbarossa as initially planned. Even if it's slower going in the Balkans than OTL the outcome is the same.