So this YouTube clip, Reddit post and other stuff i found got me wondering, could Sweden in the 1940 to 1943 period have been able to stop a German invasion.
YouTube (Could Sweden have withstood a German Blitzkrieg in WW2?)- As late as February 26th 1940 there were discussions about including Sweden in the German operation "Weserübung", but when the operation began on April 9th 1940 Sweden had been excluded. [s63]
Operationally I would have to question the ability of Germany to mount a Swedish operation before sealing off Norway and Denmark and using the occupation of both nations to gain cross straits access and logistics establishment of lodgements into southern Sweden. After the Kriegsmarine is shot up in Weserebung, the chances of getting past the Swedish navy are not too good, so operations have to come through via Norway.
It appears that any post Weserebung operation would have to be overland and would involve transportation difficulties and supply problems for the Germans south to north through the Scandinavian mountains in easter Norway. If they could get east from Oslo fjord via the rail and road net, they could work their way through the southern plain to advance on Stockholm. The lakes present a problem but not insurmountable for motorized infantry with air support. The Swedish army has too many avenues of approach and not enough means to block all the axes of adavance... (see map.)
Now some technology comments.
- Bolt-action rifles dating to the late 19th century was standard armament in all armies in ww2, with the exception of the US army - the US being the only country with the industrial capacity (and the infantry doctrine) to equip all their men with with semi-automatic rifles (except the Marine Corps, which continued to use M1903 Springfield bolt-action rifles).
1. The Americans did not totally equip with semi-auto rifles until about late 1942. Until then their national guard was still issued 1903s and pattern 1917s from the WWI stockpiles.
2. The USMC was intending to equip with Johnsons but was overruled by US logisticians who felt commonality with US Army equipment was more desirable. The NEI army bought up all the Johnson production in the meantime. The Dutch East Indies were overrun, and the USMC were stuck with 1903s into 1943, though not by their choice. - The 1925 defence decision called for 4 line divisions, but you completely miss both the motorised brigade (created out of the cavalry division that was disbanded) and the local defence/landstormen that consisted of the oldest 10 classes and was almost as large as the line army and tasked with local defence. The army was far larger than just 4 divisions and could mobilise roughly 400 000 men in 1939.
3. I did not know this. I thought the Swedish armed forces used a system similar to the Cat 1, 2, and 3 formations that the Russians pioneered in the mid 1930s.- Swedish had more artillery than that in 1939. There were 120 modernised light field guns, 200 ww1 vintage light field guns, 174 pre-ww1 light field guns (without recoil system), 160 ww1 vintage medium howitzers, 48 modern heavy field guns, 12 ww1 vintage heavy field guns, 53 pre-ww1 heavy field guns (without recoil system), 28 modern heavy howitzers, 66 ww1 vintage heavy howitzers and 12 ww1 vintage heavy siege howitzers, for a total of 227 pre-ww1, 450 ww1 vintage and 176 modern artillery pieces.
4. I make it ~ 160 field mobile guns in 1940, since without prime movers and artillery trains for the existent mobile artillery; the other older tubes are for all practical purposes ineffective?- Sweden had in active service 48 MG-armed tanks and 16 cannon-armed tanks in 1939, with 7 MG-armed and 5 cannon-armed older tanks in depots used for training. There were 25 cannon-armed and 21 MG-armed and armoured cars in active service, with 8 MG-armed armoured cars in depots used for training. Total numbers are thus 21 gun-armed and 55 MG-armed tanks and 25 cannon-armed and 29 MG-armed armoured cars.
5. How many were ergonomically two-man and three-man turret, so the commander had situation awareness? How many had radios tied back to higher headquarters or to their infantry support? Were these units deployed as cavalry or direct infantry support? The most dangerous armored units were ones that made contact, got on the radio and called in air strikes and artillery barrages on enemy troop concentrations. - Sweden had 173 planes in active service in 1939, plus around 50 planes in reserve (a mix of reserves for the active units and older planes) with a further roughly 50 trainer and liason planes. While most were biplanes, the roughly 45 B 3 (Junkers Ju 86) and 11 T 2 (Heinkel He 115) were not.
6.
The fighter force would be more important for air defense than the bombers, since the bomber force was really too small numerically to matter. Agood question to ask is; how good were the Swedish torpedoes for the He 115s, since I suspect these were "British" sour4ced and prone to British early war mechanical failings. - Sweden did not get most of her equipment abroad - all equipment save some planes were produced locally, albeit often on license. Ammunition was standard 6,5x55mm (for rifles, LMGs and MGs) and 9x21mm (for pistols and SMGs) in 1939. It was only the war that led to some imports of non-standard calibre weapons, including 7,92x57mm Mauser and the switch of the standard pistol bullet from the 9x21mm to the 9x19mm. Non-standard weapons were usually sent back to the depots and modified to standard calibres once enough arms were available and the immediate invasion threat died down.
7.
Were the Northrop Gammas locally built or kit built as in the N3PB case with Norway? Also, what was the problem between Stockholm and Washington? The arms trade with Norway seems to not have as many political hurdles, despite Norway being in much a similar political state? - Only the US feared Sweden would go over to the other side and impounded arms orders - mostly aircrafts in the form of 60 J 9 (Serversky EP-106), 58 B 6 (Repubic 2PA) and 144 J 10 (Vultee P-66 Vanguard). Sweden purchased arms from Germany (including captured Bofors weapons from Poland and Austria), Switzerland, Italy and Finland and eventually radar stations from Britain. No-one gave arms - they were paid for, and in the Italian case, through the nose in strategic materials.
8.
Refer to 7 and again ask what was the political hangup?- One needs to remember that Germany actively threatened war with Sweden if Sweden allowed Allied troops on its soil, which influenced the Swedish "no" quite a bit. Germany would not stand idly by if the Allies tried to secure the Swedish iron ore.
9.
How much tie-in was there between Swedish and German industrial concerns and did this also influence Swedish and German interactions? - The Landstorm that manned the Per-Albin line had served on average 360 days of conscription and at least 100 days of neutrality watch during ww1. To claim that they could not operate the weapons of the line is simply silly - the line had very few anti-tank weapons, mostly because tanks as part of a naval landing on a beach were not a thing in 1940 (and would remain a very minor thing until the Allies built a large amount of amphibious tanks and landing crafts for tanks for the invasion of Normandy in 1944). The Germans certainly had nothing that could land tanks at beaches in 1940.
10.
The main threat seems to be more of an overland campaign from German occupied Norway. Defense from seaborne attack was an air-sea problem. 11
. The Japanese would demonstrate just how dangerous tank landing ships were as early as 1938 along the coasts of China near Shanghai. I presume the Germans knew how train ferries could be used to land tanks onto a beach? If not, their Japanese allies could educate them with Daihatsus.
- The Swedish offensive plans against German-occupied Norway in 1941-1944 focused on Mo-i-Rana, which was the closest port to the border and also lacked a rail connection to the rest of Norway, making it a much easier target, not Narvik.
12. Agreed. Did the Swedish plans include neutralizing German airpower out of Bode?- In 1940 there were 230 000 men in the line army, and 190 000 men in local defence units, which were tactically but not operationally mobile. The local defence held down fortified lines, air fields, garrisons, cities, ports and beach defences, freeing up the line army to deploy wherever it was needed and for offensive or counter-offensive work. In 1941, this had increased to 340 000 men in the line army and 260 000 men in the local defence, plus another 100 000 in the home guard. By that time, the local defence actually had more MGs and AT guns than the line army, since they manned a lot of fixed fortifications.
13. Refer to 10?- The German intelligence on the Swedish army was beyond horrible. The officer responsible, Major Karl Ogilvie at Fremde Heere West (Foreign Armies West) simply copied the same assessment from 1939 to 1944, indicating that Sweden lacked AA capability (despite that more than 1 000 40mm Bofors guns and 1 200 20mm AA guns had been delivered to the army), lacked mechanised forces (despite Sweden having a motorised brigade since 1937 and creating 2 armoured brigades, each with 140 tanks in Summer 1943, which grew to 3 armoured brigades with 185 tanks each in early 1944) and was entirely focused on defence (despite General Rappe conducting a very skilled infantry attack in the Finnish style durin the great exercises of January 1942). The German military attaché in Sweden, Bruno von Uthmann writes in his memoirs that no German plans on Sweden was ever made, which means he was not consulted at all (and he was probably the one who knew the Swedish army the best). On the other hand, Swedish intelligence on the German forces in Norway was excellent. 2 days after 25. Panzer-division moved from Oslo to Trondheim, the new location shows up in the staff reports of II. MILO, the Swedish military area tasked with defending that part of the border. Sweden also acquired the report the German staff of the 25. Panzer-division prepared for the planned invasion (this if anything is an intelligence master-piece!). The report also included that Sweden lacked any armoured units. The Germans were completely unaware of the Swedish 9. and 10. Pansarbrigaden armoured brigades placed in reserve to counter any German armoured trusts in Summer 1943.
14.
This is 1943, correct? What was the intelligence and operational situation like in February-March 1940? - By Summer 1943, it was obvious that while the Germans might be able to conquer Sweden, they could ill afford to move the resources necessary to do so from other fronts - the resources in Norway was not enough, and Sweden's attitude changed accordingly. Sweden had 360 planes in combat units Summer 1943 - the Germans had 155 in Denmark, Norway and Finland.
15.
It is instructive that the Allies did not try a Narvik operation in 1943. The reason was simple. The Germans could air reinforce Norway and achieve air superiority in hours. The Swedish military would have faced the same problems. Add that Swedish ammunition stocks and fuel reserves would have been exhausted within days. Lose the air campaign and the ground war follows the same outcome. In 1943, the allied air forces were still not strong enough to wrest air superiority. Refer to 12? - von Schell's plan called for at least one regiment of paratroopers, 2 panzer divisions and at least 4 infantry divisions, he never had any paratroopers, only 1 panzer division (weakly equipped and completely green) and 2-3 infantry divisions, depending on how much the other divisions in Norway were cannibalised. Sweden at this time had 10 infantry divisions, 1 motorised and 2 armoured brigades (that had more tanks than the German 25. Panzer-division) as well as the local defence and the home guard, their numbes being equilent to about 10 more infantry divisions (albeing lacking in artillery).
16.
If he had a Fliegerkorps, it would have been enough. - von Schell himself commented his plan when it was discovered in the archives and then debated heatedly in Sweden in the 60s in a polite reply that he never had the forces the plan called for.
17.
That means he would not have the logistics or the air support?- The force mobilised in 1943 was 300 000 men, with another 300 000 plus 100 000 in the Home Guard available for mobilisation. They were mobilised because Sweden planned to cancel the transition treaty and wanted to be ready for a potential German armed response, or at least make a show of force to discourage the Germans from any armed response. Sweden knew the Germans had a panzer division in Norway and closely tracked its movement, but did not know the details of the German plan - it was discovered in the 60s.
18.
How good was Swedish preparations for an air campaign? France 1940 was decided as much in the air as it was at the Meuse bridges and in the Ardennes. That huge battering ram of German infantry behind that small panzer spearhead was what really split the French defense. The AdA was unable to drop the bridges or bomb the huge 70 kilometer long bumper to bumper German traffic jam in the Ardennes during the critical 73 houses at the Meuse. - Sweden did not fear a communist take-over of Denmark and Norway. The "police" troops were created to give the Norwegian and Danish governments a reliable force to establish order after a German collapse (or perhaps even invade if the German forces refused to surrender after Berlin did), arrest collaborators and prevent the Germans from taking civilians as hostages or destroying evidence of their war crimes.
19.
Something else I did not know.- You keep consistently call mortars "grenade launchers" - there's a substantial difference. Mortars were quick-fire weapons with dedicated crews and forward observers, grenade launchers were attached to rifles and used by the infantry to throw hand grenade sized rifle grenades further than a man could throw them, but much shorter and with a much lower rate of fire than mortars.
20.
The Germans called their mortars, "grenade throwers" (English translation.). I suppose this spills over since water bombs (German for depth charges.) were also a form of grenade in naval warfare and the "water bomb thrower" was akin to the K-gun or "spigot depth charge mortar"? Terminology does not translate well across languages. 
