Sweden in World War II - across borders

Swedish intelligence

In 1937 the Swedish minister in Berlin had come to the conclusion that everything said on the telephone probably could be intercepted by the Germans, and maybe other conversations too. The suggestion was to let Swedish workers install a new telephone system. [s67]

This was refused from Stockholm. If Sweden did so, probably the Germans in Stockholm would demand the same thing in the German embassy in Stockholm. [s67]

The secret Swedish intelligence service had been closed down in 1932. It wasn't until after the Soviet Union attacked Finland on 30 November 1939 that the Swedish authorities again funded an intelligence service. [s53]

Meanwhile the Swedish defence staff had received information from various sources, among others Swedish military attachées and various more personal contacts between Swedes and people from other nations. One such contact made a Swedish attaché in Berlin suspect that Denmark and Norway would be attacked by Germany in April 1940 - but not Sweden. [s53]

The Swedish military intelligence kept an eye on the Swedes who had fought in Spain during the civil war. In a document it was written that many of them got more education, even special education, in the Soviet Union, where their stay was not impossible to establish. [s50]

The Swedish defence staff could read secret German military and political messages between May 1940 and June 1942. It was messages sent to and from the higher military staff in Norway, and to and from the German legation in Stockholm, and later also to and from the higher military staff in Finland. The code used in the German so called Geheimschreiber were deciphered by the Swedish mathematician Arne Beurling in May 1940. From the autumn of 1940 the deciphering worked so well, with a deciphering machine made by Beurling, that the Swedish defence staff knew the content of the secret messages almost as fast as the German receivers. [s53]

One important fact was Sweden's geographical location. The German legation in Stockholm rented a telegram/telephone connection Stockholm-Berlin, and later added Stockholm-Helsinki (Finland). In connection to the German attack on Denmark and Norway, Germany had made an agreement with Sweden. The German telegram/telephone traffic should be sent via Sweden in the connections Oslo-Copenhagen-Berlin, Oslo-Stockholm, Oslo-Trondheim and Oslo-Narvik. There could be up to a hundred telegrams per day. Later it was estimated that some 75% of the intelligence information Sweden had collected came from these telegrams. [s53]

On 10 September 1941 a telegram from Norway to the supreme command in Germany declared that the German national commissioner in Norway, Josef Terboven, would declare a civilian curfew in the Oslo area that night. The reason was to handle strikes by Norwegians. Hitler's answer was that the strike leaders should be detained during the night and in secrecy be sent to a concentration camp. [s53]

Not all secret German messages were sent via the Geheimschreiber, and it was not only military secret that were sent via this encoded system. There were also gossips, private shopping lists, family news et cetera. [s53]

Some messages were of more direct interest to Sweden, among others the messages between the German foreign office and their legation in Stockholm. There were also telegrams with specifications of the content in railway cars transported via Sweden. Other telegrams to the German air force and naval forces in Denmark and Norway specified which Swedish "lejdtrafiken" merchant ships that had been allowed to pass through the German blockade in Kattegatt and Skagerak. [s53]

It was very important that the Swedish code breaking was kept secret, so only a few got information from it and often delivered in a well disguised form. One example: At the end of May 1941 Swedes knew that Germany would attack the Soviet Union, and they felt sure that Germany had no plans against Sweden. So during the Swedish Midsummer holiday in the second half of June 1941 the Swedish military leadership was on leave. Sweden seemed to be completely unaware of the German attack on the Soviet Union. [s53]

However there were leaks. One soldier, who transported deciphered messages to the defence staff and the foreign office, took photographs of messages between August 1941 and January 1942 and gave copies to the Soviet Union. Later an officer in the defence staff told the British about German naval forces in Norway, and it is believed that the British understood what the Swedish source was. On 19 June 1942 Sweden intercepted telephone conversations between German Luftwaffe units in Oslo and Rovaniemi (in Finland) where it was clear that the German army headquarter in Norway had forbidden telegrams coded with the Geheimschreiber to be sent via Sweden, since the Swedes could read them. Apparently the Germans got this information in Finland. It took a short time until the military messages were stopped completely, but the German foreign office kept on with the communication until 1943. [s53]

Information retrieved by the Swedish intelligence was documented in reports to a few selected receivers. Here are a few fragments of information in some reports between 30 June 1941 and June 1942. I have foremost focused on information that could be relevant to Sweden, in case of changes on the fronts between Germany and the Allies, but included some fragments to show the width and detail of the information.

  • 30 June 1941: The German 163 infantry division 'Engelbrecht', transported from Norway via Sweden to Finland, was planned to be sent to the Karelian Isthmus.
  • 10 July: The larger Soviet Union naval ships sailed further east in the Gulf of Finland.
  • 1 August: German air reconnaissance counted to 146 Soviet Union airplanes in the area Murmansk Kandalakscha.
  • 9 August: Reinforcement of German air force in northern Norway and Finland. British air raids on Petsamo and Kirkenes may have contributed to the reinforcement. Air fields in northern Finland can't be used by heavy bombers, but construction work would be finished around 10 August. Ground crew in K.G.28 moved from Paris to Rovaniemi in Finland.
  • 19 August: Around 50 Finnish fishing boats and some tug boats will be used to land German troops on the smaller islands around the Soviet Union island Reval, after the Germans take over Reval.
  • 26 August: The Germans prepare for a British invasion in the Murmansk area in the Soviet Union. If that happens, all aircrafts in northern Norway and Finland shall be used to counter this invasion. Preparations to receive reinforcements to the airfields in Petsamo (Me 109) and Kirkenes (Me 110), and preparations for intermediate landings on named airfields. Also a list of places in northern Norway where extra searchlights would be installed.
  • 26 August: New German fighter, FW 140, has been tested in air combats with British RAF. Positive results for the FW 140 in fights with Spitfires.
  • 26 August: The Soviet Union use bombers stationed on Dagö for air reconnaissance over Finnish and German sea transports on the Gulf of Finland and the Baltic Sea. Also along the Swedish coast, usually on 4.000 metres height and close enough to land to observe ships that sail inside the skerries.
  • 3 September: A PM from the German Luftflotte 5 told that the German air force in northern Finland would not be able to give good support to the ground troops from September, due to the winter climate. Neither the Soviet Union would not be able to perform air operations. The high command of the Army had commented to the PM, that both parties had had extensive air operations during the Finnish-Soviet Union winter war in 1939-1940, when the largest Soviet Union air raids on among others Rovaniemi took place in January (in the midst of hte winter season).
  • 3 September: A British naval force with seemingly 2 light cruisers, 1 carrier, 7 destroyers and 1 tanker operates from early September in the Arctic Ocean. A destroyer attack on a German troop carrier convoy at mid day on 7 September, where one ship was sunk, led to a German request/suggestion that following troop cariers should either stay in certain Norwegian ports or be redirected via the Baltic Sea to Finland.
  • 3 October: VII army korps (1, 4 and 11 divisions) have continued the attack on Petrosavodsk partly along the railway Suojärvi-Petrosavodsk and partly over Prääshä and reached west Souju-Petrosavodsk. Attack continues.
  • 3 October: The German battleship Tirpitz, the heavy cruiser Admiral Scheer, 2 light cruisers, 1 destroyer and 2 other ships was in Åland (between Sweden and Finland) in September, probably as a precaution for a Soviet Union attempt to sail out of the Gulf of Finland after heavy German bomb raids on 23 September.
  • 6 November: German air attacks on ships in the north has been concentrated on Soviet Union ice breakers. Several British warships observed in the Arctic Ocean. Supposedly several British convoys had reached the Soviet Union port Arkangelsk, and USA shipments of war material would also begin to sail to Arkangelsk. The Germans have taken over the Finnish air field in Pori, and extensive enlargement work is going on. Pori will be the nave for transit traffic from northern Norway and northern Finland over Sweden to Oslo, and on to Germany.
  • 27 November: Soviet Union crews are fast to repair railways destroyed by German bombs. German concentration on railway attacks had led to fewer attacks on Soviet Union airfields, and Soviet Union air activities had increased. New German orders to attack enemy air fields under all circumstances.
  • 17 December: British and Soviet Union submarines have radio contacts with radio operator in or near Hammerfest (in northern Norway).
  • 22 January 1942: Rather detailed information about British landings and attacks along the Norwegian coast between 26 December and 7 January. Norwegian pilots and road guides participated in attacks, that were filmed. It was supposed that the foremost purpose of these attacks was to stimulate the Norwegian resistance, but also to disturb German shipping and test the German coastal defence. The report included a list over the Soviet Union fleet in the Baltic Sea and the present condition of each ship, and Soviet Union air force units north of Moscow including airplane models. Of the foreign airplanes the USA Tomahawk is especially noticed.
  • 24 February: XVIII Gebirgskorps in Finland has not received further units, due to the ice conditions in the Baltic Sea. Large German transport problems in the north with extended use of railways, which has caused some occassional disorder. Probably changes due to preservation of fuel at the prospect of the spring offensive on the Soviet Union, problems to keep roads open and that the car tyres from Buna can't stand the strain of the low temperatures.
  • 1 April: Large German reinforcements to Norway and reorganisations are described. Among the other pages of information are the sizes of troops from Bulgaria, Hungary, Italy (reinforcements) and Romania who fight with Germany against the Soviet Union. The sizes of the German and Italian forces in Libya is also noted, and a comment that there are intensive preparations for an offensive - probably on Tobruk.
  • 1 April: From the beginning of the war against the Soviet Union on 22 June 1941 and until 8 March 1942, the Finnish air force had lost 54 fighters and 17 bombers. They had shot down 406 enemy aircrafts, and Finnish anti-aircraft gun crews had shot down 355 aircrafts.
  • 1 April: That report also had a chapter about the Allies most important task which seemed to be to send as much war material and other wares as possible to the Soviet Union, so they could maintain their resistance towards the German forces. The shortest route is through the Arctic Ocean to the ports in Murmansk and Arkangelsk (closed at the time due to the ice conditions). The other important task was to create a second front in Europe, and Germany saw an invasion effort in northern Norway as possible. That would be a threat to the nickel mines in northern Finland that was vital to Germany. Germany had made extensive measures to stop the Allied convoys to the Soviet Union.
  • 12 May: The Soviet Union attacks on the Liza- and Kiestinki fronts caused an exception from the German air force's focus on the Allied convoys to the Soviet Union. A division of Stukas supported the ground troops, and a division of Ju 88 bombers were moved to Kemi. Other bomber units were moved from among others Holland to northern Norway, and a torpedo unit was sent from Grosseto in Italy to the Norwegian Porsangerfjorden.
  • 12 May: Some of the problems for the German hunt for the Allied convoys: Bad weather with poor visibility, strong guard of convoys, arrival of summer with longer days and lighter nights (hazard for submarines) and thaw (damaged runways on airfields), destroyers iced up due to cold and wet weather, and too bad weather for motor torpedo boats. Presumably also 4 USA submarines operate in Norwegian waters, among others Sargo and Sculpin.
  • 16 June: Soviet Union have dropped German ammunition behind the German lines, but instead of gun powder there was explosives that caused the weapons to explode when the ammunition was used. Since mid May 1942 the Soviet Union had received substantial deliveries of war material, foremost British Hurricane and USA Tomahawk fighters. On 19 May the first sighting of USA fighter Curtiss P-40 with USA emblems. Strong concentration of Soviet Union fighters in the Murmansk area, which Germany see as partly defence against repeated German air attacks, protect the workshops where British and USA airplanes are assembled, and to protect a possible Allied landing in the Petsamo-Kirkenes area. [s53]

    Swedish officers visited various warfaring nations during the war, on both sides, among others to learn of their experiences. [s75]

    The Swedish defence staff could also read secret Polish messages. [s67]

    On 18 May 1941 the new German warship Bismarck and the heavy cruiser Prinz Eugen left Gdynia in the occupied Poland. They sailed through Kattegatt on their way to the Atlantic on the evening of 20 May. [s39]

    Crew on a Swedish cruiser reported the sighting of two large warships with escorts and air cover on the way towards the Atlantic. This information found the way to Britain's naval attaché in Stockholm, who forwarded the message to Britain - and the hunt for Bismarck began. [s38]

    The information had been given by a Swedish major in the Swedish Intelligence Service to the Norwegian military attaché, who passed it on to the British. [s57]

    (One week later Bismarck was sunk. [s39])

    (Britain had not discovered any Enigma traffic about the departure of Bismarck, and the transmissions from Bismarck during the following week were not decrypted until after she was sunk. [s38])

    (The Swedish cruiser was "Gotland", which was 'half cruiser and half carrier' for 6 planes. [s70])

    Air craft cruiser Gotland, built in 1933-1934 by Lindholmen and Götaverken

    The Swedish military attaché in Berlin wrote in a report to Sweden on 1 October 1941 that a German officer on the eastern front had said, that they didn't capture war prisoners besides when they captured larger numbers of Soviet Union soldiers. [s50]

    A report from 29 October 1941 had information from a Swedish officer in Waffen-SS. He had said that people in occupied villages in the Soviet Union told SS-Sonderkommandos about who were jews, and the jews were executed. A German magazine for front soldiers had mentioned that the jew issue in Russia would be solved in a radical way. [s50]

    The Swedish consul in Stettin reported about German troops and ships in northern ports of Germany. Towards the end of 1941 he reported about the extermination of Jews in the Baltic countries. He was ordered to leave Germany in mid 1942. [s67]

    On 12 August 1941 the first convoy with war material for the Soviet Union left Britain, with among others 20 tanks and 193 figher planes. It arrived in Archangelsk on 31 August, with no losses on the route that passed rather close to the north Norwegian coast, and it was followed by more convoys. The first heavy losses occured on 27 March 1942, when 20 merchant ships were attacked by 108 German warplanes. Five merchant ships and two escorting destroyers were sunk. Another threath was that the German battleship Tirpitz and other warships had been stationed in northern Norway. One day in July 1942 there was suspence in the British admiralitys intelligence office, regarding one of the convoys. Was Tirpitz still anchored in the Altafjord in Norway, or had she and support vessels gone to sea? One piece of information was a German radio transmission that had been intercepted in Sweden. (The Allies freighted 4 000 000 metric tonnes of equipment to northwestern Soviet Union with these convoys, 22,5% of the total British and USA support to the Soviet Union, among others 5000 tanks and more than 7000 planes.) [s51]

    In Kronstadt, in the Soviet Union, a smaller naval convoy was assembled on 30 October 1941. A Swedish intelligence message on 2 November informed that the ships had passed Helsinki in Finland around 02.45 during the night sailing westwards. The message said that the smaller ships in the convoy did not seem able to sail all the way to the Swedish coast. (The purpose of the convoy was to begin the evacuation of the Soviet Union naval base on Hangö in Finland.). [s59]

    Between 22 June 1941 and 1 March 1942 1.600.000 Germans were killed on the eastern front, 400.000 were badly injured and 1.000.000 had got other injuries, reported the Swedish military attaché in Berlin. He also reported that all retired officers up to the age of 70 and to the rank of major-general had been drafted, and that Germans in farming an industrial work more extensively were replaced by war prisoners and forced labour. [s53]

    The Swedish naval attaché in Helsinki, Finland, had access to various information. Among others German reconnaissance photos over the Soviet Union's naval base in Kronstadt. [s59]

    Swedish intelligence among others got information from listening to telephone wires that passed through Sweden, and to decipher telegrams. German naval forces in northern Norway was one area of interest for the allies, and the chief for a foreign section in the defence staff gave some information (acting on his own responsibility) to the British marine attaché Henry Denham in Stockholm. One occassion in the summer of 1942 regarded the allied convoy PQ17 to the Soviet Union. Denham had been told about the German operation Rösselsprung, to use the battleship Tirpitz and the cruisers Hipper and Scheer to attack PQ17 outside the Norwegian coast. In short about some of the 'miss:es' from various parts: On 3 July a British reconnaissance plane had confirmed that Tirpitz had left the Norwegian fjord where she had been, and the First Sea Lord in London believed that Tirpitz was on the way to PQ17 and gave in the evening of 4 July the order to scatter the convoy. Eight hours before that order was given, the Swedish intelligence had intercepted a telephone call between Kiel and Narvik where it clearly was stated that the operation Rösselsprung had been cancelled. But since it was during a weekend the Swedish chief didn't get that information until after the weekend. The large German warships had just been relocated among the Norwegian fjords, but other German forces attacked the scattered merchant ships. Of the 39 merchant ships in PQ17 only 12 managed to reach ports in the Soviet Union. [s71]

    The Swedish supreme commander got information about the chiefs contacts with Denham during the autumn of 1942, and the chief lost his position at once and seemingly there also was something said about a possible court-martial. However the Swedish foreign office was not informed. In around the same period, the undersecretary of state for foreign affairs told the new deputy chief in the defence staff to 'end the favouring of the defence attachées from the Axis Powers, and more address those for the Allies who by good reasons feel neglected'. [s71]

    ( PQ17 had 36 merchant ships when it left Reykjavik on Iceland, escorted by 23 naval ships of various types. There was also a close distance force that consisted of 4 heavy cruisers and 3 destroyers, and British Home Fleet's main force went to sea as a distance protection fleet with 1 carrier, 2 battleships, 2 cruisers and 14 destroyers. One merchant ship ran aground near Iceland, and one was damaged by the pack ice in the Denmark strait. 11 ships arrived to Soviet Union ports 10-25 July. With the sunk ships the Allies also lost many sailors, and among others 210 planes, 430 tanks and 3,350 vehicles. [s39] )

    In 1943 Swedish reconnaissance planes had taken photos of the German test site in Peenemünde. Info was given to the British, as part of the intelligence cooperation. In June 1944 a V2 rocket landed in Sweden, and a technical report was sent to Britain together with parts of the V2. (In exchange for the V2 info, Sweden got info about among others jet engines.) [s75]

    On 24 December 1943 a Swedish volunteer in Waffen-SS 1941-1943 was questioned by Swedish security police. Among others he told them about a conversation with a German in a special SS company. The German had told that the company had killed around 300000 jews during five months in the occupied areas south of Kiev, with machine guns or in buses that had been filled with exhaust from the engine. [s50]

    In June 1944 the Swedish military attaché in Berlin was given a photo and facts about the new German anti-tank weapon Panzerschreck. It was given by three Swedes who served for SS. [s50]

    2019-04-07. www.granfoss.se. Text/pictures: Arne Granfoss