Sweden’s role in World War II has evoked little interest outside of that country. Although we now know this nation would never enter the war, Hitler and Dönitz could not count on this. For Hitler Sweden represented a valuable source of raw materials and manufactured goods, as well as a possible threat to Germany’s position in Norway. To Dönitz this politically unreliable nation’s location potentially endangered the navy’s U-boat training areas in the Baltic. Particularly in the final stage of the war, both Hitler and Dönitz endeavored to ensure at all costs that Sweden remained neutral.
On several occasions Hitler claimed a political motive for retaining a foothold in the Baltic States. He feared that withdrawing from Estonia, and later from Courland, would adversely affect Sweden’s attitude. Hitler believed that the presence of German troops in the Baltic States deterred Sweden from cutting off ore imports. On 5 September 1944, when Army Group North wished to evacuate Estonia in the wake of Finland’s surrender, Hitler insisted that holding the current positions in that sector was politically important as a way of exerting influence on Sweden. Two days later Natzmer phoned OKH to check on the army group’s request to retreat; Berlin replied that Guderian had attempted to convince Hitler to give up the Baltic States but that Hitler had again brought up his concern for Sweden. In the winter and spring of 1945 Hitler returned to this theme, at times responding to Guderian’s demands to evacuate Courland by insisting that only the presence of the Courland armies prevented Sweden from declaring war on Germany. To understand why Hitler feared Swedish belligerence and whether the Swedes had given him cause for suspicion, a brief review of Sweden’s policy since 1939 is necessary.
Upon the outbreak of war Sweden declared its neutrality and continued to trade with both Britain and Germany. Sweden experienced few problems until the end of November 1939, when the Soviet Union attacked Finland. Sweden found itself in a precarious situation during the Winter War, as it had long maintained very close ties to Finland and traditionally feared Russia. The Swedish government was willing to assist the Finns in almost any way possible, short of war. Sweden provided Finland with substantial aid and sent large quantities of arms and ammunition, seriously depleting its own stocks. The Winter War also brought difficulty on the diplomatic front. Determined to prevent Swedish belligerency, Germany sent several thinly veiled threats demanding that Sweden remain neutral. Hitler feared that Sweden’s entry into the war would jeopardize the delivery of iron ore and that if Russia attacked Sweden, it would be difficult for the Swedes to refuse Allied offers to intervene in Scandinavia. The Germans warned the Swedish government that they would take swift action if Allied troops entered the country. Hitler’s anxiety in this matter was justified, because the British and French made repeated requests that Allied troops be allowed to pass through Sweden to aid Finland; Sweden refused them. The end of the Winter War in March 1940 did not lessen the danger to Sweden, for on 9 April Hitler invaded Norway and Denmark. Although a Swedish military attaché had alerted Defense Minister Per Edvin Sköld, this warning went unheeded.3 Sweden’s military position at this time was even worse than in autumn 1939. Southern Sweden was virtually defenseless, because the Swedes had concentrated their army in the north during the Winter War, and the delivery of arms and ammunition to Finland had deprived Sweden of a significant proportion of the supplies needed for its own defense.
Admiral Raeder provided Hitler with convincing naval arguments for the occupation of Norway, but Hitler’s interest in guaranteeing supplies of Swedish iron also played a role. The Winter War and the danger of Allied intervention in Scandinavia had revealed the threat to Germany’s ore imports. Swedish iron ore reached Germany by two main routes. The Swedes shipped some from ports in the Gulf of Bothnia, mainly Luleå, but most of these ports were closed nearly half the year due to ice. The preferred route was to send the ore to the Norwegian port of Narvik, ice free throughout the year, for transshipment to Germany. Yet with the outbreak of war the Narvik route proved vulnerable to British interference.
Churchill considered halting iron ore shipments to Germany decisive. The British predicted that without these imports German production would cease within months, if not weeks (an assessment that greatly exaggerated the importance of Swedish iron ore to Germany’s war economy). In April 1939 British trade envoys tactlessly warned the Swedes that in the event of war, Britain might have to destroy the iron mines. A major reason for Britain’s interest in assisting Finland during the Winter War was to occupy Sweden’s iron mines.6 In the end the British decided not to take military action against Sweden, but they did mine Norway’s coastal waters and planned to sabotage port facilities at Oxelösund, an ice-free port on Sweden’s southeastern coast from which Germany received ore. During the fighting in Norway in the spring of 1940 the British destroyed port installations at Narvik, significantly reducing its capacity for ore shipments.
Swedish iron ore was of a very high quality, having an iron content of nearly 60 percent, compared to 30 percent for German ores. Germany obtained most of its iron ore from the Reich and Nazi-occupied areas, but about 80 percent of the iron ore it did import came from Sweden. Another vital import was ball bearings. The Nazis received no more than 10 percent of their ball bearings from the Swedes, but these bearings were of the types Germany lacked later in the war due to Allied air raids. Germany also imported from Sweden high-grade steel, finished copper, sulfur, and timber.
After the occupation of Norway and Denmark, German pressure on Sweden increased. Eager to remain at peace, the Swedes granted more and more concessions to Germany. Churchill feared that the Swedes would purchase their neutrality by supplying Germany with all the ore it wanted.9 But in fact Sweden granted the Germans far more than raw materials; its government stretched neutrality past any recognized limits. Hitler had demanded strict neutrality from Sweden in April 1940, when such a policy benefited the Nazis, and the Swedes had agreed on the condition they be left in peace. After the conquest of Norway, Germany received permission for so-called transit traffic, the transport of supplies and soldiers on leave to northern Norway via Swedish rail lines. From June 1940 until November 1943 Sweden’s railroads carried over two million men on leave, more than 700,000 tons of military supplies, and 60,000 wounded (mainly from the front in Finland), many of the wounded on Swedish hospital trains. The Swedes justified these concessions by claiming that once Norway surrendered, these actions did not support or aid a belligerent.
In 1941 and 1942 foreign observers noted a decidedly pro-Nazi stance among many Swedish officials. In March 1941 the Swedish Defense Staff’s naval section prepared a study on a possible Russo-German war that mentioned the possibility of Germany transporting troops to Finland on Sweden’s railroads and hinted at Swedish forces fighting alongside Germans. In January 1942 Goebbels noted in his diary that Sweden had “done more for the German war effort than is generally assumed,” although a few months later he began to complain of the Swedes’ attitude. Sweden was, however, under Nazi pressure. In February 1941 its military attaché to Germany, Curt Juhlin-Dannfelt, spoke with the German Army chief of staff, Halder, about the possibility of granting transit rights to Allied troops if the Soviets attacked Finland again. Halder replied that if Sweden did so, Germany would reduce the nation to rubble. In the spring of 1941 the supreme commander of Sweden’s armed forces, Gen. Olof Thörnell, informed his government that Sweden could not withstand an attack and advised that war with Germany should be avoided if at all possible.
During the planning for the Russian campaign, the Germans hoped for Swedish assistance. The Skl (Seekriegsleitung or Skl (Maritime Warfare Command)) contemplated Sweden’s help in several matters, including laying minefields in its territorial waters to supplement those laid by the German Navy, allowing shipment of supplies for troops in Finland to southern Sweden, and protecting German merchant vessels in Swedish waters with Swedish warships. Hitler declared that he believed the Swedes would participate in the war in return for cession of the Åland Islands, and in early May OKW even considered how to use Sweden’s armed forces if they joined in the war with Russia.
Hitler had little reason to doubt Sweden’s good will in this period. Immediately after the invasion of the Soviet Union, its government allowed the Germans to transfer a fully equipped division through Sweden to Finland. This represented Sweden’s most flagrant breach of neutrality. The Swedes refused transit rights for a second division at the end of July 1941 but later permitted the transport of an SS battalion. In addition, the government doubled the normal allowed leave traffic. Swedes also provided a valuable service by repairing all types of vehicles from German units in northern Norway and Finland, saving the Nazis a great deal of time and transport space. Furthermore, Sweden allowed German merchant vessels to pass through its territorial waters, and on one occasion a German division sailed from Norway to Finland through Swedish waters. Despite the pro-German attitude of several prominent military and political leaders, however, Sweden’s press was virulently anti-German, frequently enraging Hitler and above all Goebbels. In the fall of 1940 the government confiscated several issues of the Göteborgs Handelstidning to placate the Germans and in June 1941 introduced a law curtailing freedom of the press.
Britain’s naval attaché in Sweden, Henry Denham, claimed that the Swedish Navy was especially pro-German. Denham also charged that the Swedish secret police worked very closely with German intelligence and kept track of his movements. Thörnell himself had a reputation for being very pro-German. In April 1941 he suggested to the government that Sweden participate in an anticipated war against the Soviets, and at the end of 1944 Thörnell reportedly was almost in tears over Germany’s defeats.
Yet the Swedes made most concessions during the years of German victory. The declaration of war on the United States, the Allied landings in North Africa, and the Soviet victory at Stalingrad caused Sweden to reassess its relations with Germany. During the second half of 1943, once Sweden had built up its armed forces to a respectable level, the Swedes began to restrict concessions previously granted. In August the Swedish government informed the Germans that it would halt the transit traffic to northern Norway and that it would no longer allow German vessels in Swedish territorial waters. Once the Swedes began to steer away from Germany, they came under increasingly heavy pressure from the Anglo-Americans to reduce exports to Germany, especially ball bearings.
Hitler viewed Sweden’s increased independence with growing mistrust. At the end of 1941 he feared the British might invade Norway to exert pressure on Sweden, and only a month later he began to suspect Swedish hostility, claiming that the Swedes would support a British landing in Scandinavia. Hitler declared that Allied domination of Sweden would deprive Germany of freedom of movement in the Baltic. In April of 1942 he notified Mussolini that Sweden would defect if the British invaded Norway. Explaining that a link between Britain and Sweden would be dangerous for Germany, he informed his Italian ally that he had reinforced Norway with seventy thousand men and deployed an armored division near Oslo to threaten Sweden. The Germans received reports that the Allied landings in North Africa in November 1942 had made a profound impression in Sweden. To this Hitler declared that Scandinavia’s protection was more important than a major offensive in Russia for the coming year, and he accordingly ordered the armored division in Norway reinforced. Hitler’s reaction to Sweden’s announcement ending the transit traffic to Norway, however, was surprisingly calm. By the fall of 1943 Jodl too was convinced that a successful Allied landing in Norway would bring Sweden into the war, leading to the collapse of the entire Scandinavian front and endangering the Baltic.
Swedish intelligence rendered an invaluable service to its government by cracking Germany’s codes at a relatively early date. In April 1940 the German military rented telephone and telegraph lines between Narvik and Oslo, and Trondheim and Oslo, which passed through Swedish territory. The Swedes promptly tapped these lines, as well as German lines from Berlin, Oslo, and Helsinki to Stockholm. Although in the beginning the Swedes read only military traffic, a direct line from Berlin to the German legation in Stockholm at the end of 1940 yielded diplomatic messages. A mathematics professor at Uppsala University, Arne Beurling, succeeded in forcing the machine code (Geheimschreiber) used by the Germans for communications with Norway, and he built a deciphering machine of his own. In this way the Swedes learned of Hitler’s preparations to invade Russia by the spring of 1941. Swedish intelligence also provided the government with advance warning of German intentions in diplomatic and economic negotiations. In mid-1942, however, the Finns alerted the Germans to Swedish code-breaking activity, and the Nazis tightened their communications security. The Germans transferred many of their communication wires to underwater cables and introduced more sophisticated code machines, so that after the end of 1942 Swedish intelligence rarely could decrypt German messages. The Swedes assumed that by this time the greatest danger had passed, because Germany had been forced on the defensive, but they were dangerously mistaken. The Swedes lost the ability to read German messages just as Hitler was seriously considering invading the country.
Nazi Germany contemplated attacking Sweden on several occasions throughout the war. In planning for the invasion of Norway at the end of February 1940, one of Warlimont’s subordinates in OKW submitted a proposal to occupy parts of Denmark and Sweden. Interest in Sweden’s iron ore was evident in this plan, which called for the seizure of Luleå and the rail line Luleå–Narvik. Warlimont altered the plan to envision the occupation of all of Denmark, leaving the Swedes alone, because on 1 March Hitler had ordered that no moves be made against Sweden. German suspicion of Sweden’s unreliability, however, increased. In January 1943 OKW noted that reports from Stockholm and Helsinki indicated the Swedes would suspend transit traffic if the Allies invaded Norway, concluding for that reason that German troops in northern Norway and northern Finland required additional supplies. In March, Hitler ordered German forces in Norway to prepare a study for operations in Scandinavia in the event of a change in the military or political situation. He also commanded OKW not to issue this order in writing but to impart its contents orally to staff officers from Norway and Finland who would soon be coming to Führer Headquarters. A few days later Hitler’s mistrust of Sweden had grown even deeper. He commanded Jodl to reinforce German troops in Norway and to provide the armored division there with the heaviest offensive weapons, against which the Swedes had no defense.
The plan to invade Sweden envisioned an assault by a half-dozen divisions. In the north one division was to cross the border east of Trondheim toward Östersund and then thrust to the Gulf of Bothnia, supported by an armored division advancing somewhat farther south. In the south two to three divisions were to storm the frontier and drive on Stockholm, while one to two divisions dealt with Swedish troops near Lake Vänern. In addition, the Germans planned several small-scale amphibious and airborne landings on Sweden’s southwest coast and north of Stockholm to tie down Swedish reserves. At the beginning of 1943 the Germans had twelve divisions in Norway, including one armored division, and from April through June OKW sent further reinforcements. Yet in August, following the reverses Germany suffered in the summer of 1943, Hitler ordered the armored division to the continent, and the following month OKW transferred a division from Norway to the Balkans. This stripped German forces in Norway of operational reserves and ended the serious threat of invasion.
Swedish war plans during World War II reveal a surprising, perhaps overoptimistic, confidence and aggressiveness after 1940. In the early interwar years Swedish planning had focused on two potential enemies, the Soviets and an unnamed western power, presumably Britain. In view of the international situation in the late 1930s, in 1939 the Swedes revised their plans to include war with Germany. When Germany occupied of Norway and Denmark, Sweden suddenly faced a hostile power along its 1,200-kilometer-long western border, as well as to the south in Denmark. Sweden’s 1940 plans were entirely defensive and called for concentrating most of its army in the southern and central part of the country. Swedish plans in early 1941 again emphasized defense against a possible German attack from Norway, but now the Swedes began to show signs of greater confidence. They assumed that with Germany’s depleted naval forces heavily engaged against Britain, the anticipated German attack on the Soviet Union would make Sweden’s fleet an important factor in the Baltic and that their army could seriously threaten Germany’s position in Norway. Nonetheless, this plan proposed a benevolent attitude toward Germany, since it was in Sweden’s interest to see the Soviets defeated. Plans from the autumn of that year provided for minor offensive action across the border into Norway—for example, to cut the rail link to Trondheim. By early 1942 the Swedes felt capable of an offensive to seize a Norwegian port to establish a link to Britain. The Swedes showed, however, a particular fear of airborne assault, against which they had no defense. In 1943 Sweden’s army planned, after repulsing a German invasion, for an attack toward Oslo as well as a thrust to capture the port Mo i Rana, approximately midway between Narvik and Trondheim. The 1943 plans remained essentially unchanged until the end of the war. Beginning in 1944, however, the Swedes began to pay closer attention to a possible threat from the Soviets.
The Swedish Navy’s primary task was coastal defense. Since the army would concentrate its forces on the southern coast and along the Norwegian border, the burden of protecting Sweden’s long eastern shore fell to the navy. On the whole, the navy viewed its mission as defensive. By the spring of 1942 the Swedish Navy’s plans included provisions for limited offensive operations. If Germany controlled the Åland Islands the navy planned to attack supply routes to the islands. If the islands remained unoccupied, the navy intended attacks on German lines of communication in the Gulf of Bothnia, as well as on German bases in the Reval–Libau area. Surprisingly, the navy’s plans at the end of 1942 were much more pessimistic than in earlier years. The Swedes now realized that the Germans might invade not only from Norway, Denmark, or northern Germany but from Finland or the Baltic States as well. Swedish planners envisioned German landings almost everywhere. Plans in later years were not quite so gloomy, though they remained generally defensive.
If by the fall of 1943 the German Army rarely considered attacking Sweden, the navy still eyed Sweden with suspicion. The Swedish Navy was probably the most pro-German of all branches of its armed forces, but the Skl was dissatisfied. In April 1941 Raeder had complained to the Swedish naval attaché, Anders Forshell, about Sweden’s attitude. The Swedish Navy, however, proved extremely accommodating on several occasions. In the spring of 1940 Sweden’s naval vessels assisted the Germans in laying an antisubmarine net in the Sound between Denmark and Sweden (Öresund). In June 1941 the Swedish Navy laid mines in its territorial waters to supplement German mine barrages that blocked the Baltic from Swedish waters to the coast of the Baltic States. In addition, in the fall of that year Swedish warships repeatedly escorted German vessels carrying supplies to Finland.