Intelligence liaison in practice; service attachés in the Swedish Legation in London 1939-45

ABSTRACT During the Second World War, Britain was regarded by neutral Sweden as an important source of intelligence. Swedish service attachés were posted to London to use their diplomatic and service status to collect and report relevant intelligence to Swedish High Command in Stockholm for assessment and circulation. Their collection techniques in Britain meet Wilhelm Agrell’s definition of intelligence liaison and this paper describes how they were able to deliver significant results under difficult conditions. At times, they had to contend with a hostile and restrictive host country, communication difficulties (in every sense) with Stockholm and unappreciative diplomats and senior officers. Their efforts have gone largely un-noticed in Swedish Second World War historiography, and readers may be surprised to learn of the results that they achieved and the difficulties that they faced.

removal of one of the items in the sequence.There are subject registers, but these can be vague and non-specific as to subject.This review has not covered the analysis and use of the intelligence by the service branches in Sweden following receipt which would require significant further research and access to applicable records.
The archival research has been supplemented by the very few relevant memoirs of both British and Swedish diplomats and attachés.
Due to space limitations, specific archive citation for over 100 documents has been omitted and the reader is referred to the archive list in the bibliography.competent to assist the Naval Attaché and when the Army and Navy Attachés decided in mid-1943 to release him, the Air Attaché, Cervell attempted unsuccessfully to retain him.Carlbom's shifting arrangements generated a great deal of Stockholm-London correspondence and friction about workload and support.von Essen noted, 'Sometimes you don't know where he belongs.'

Navy (See Tables 1 & 2)
The navy was also represented by some weighty titles.From 1939 until 1942 Captain Nils Wesström was an exception but he was followed by Johan Gabriel Oxenstierna af Korsholm och Wasa from March 1942 until 1943.A member of the more recent Bernadotte lineage, King Gustav's son, Prince Bertil, Duke of Halland took over in 1943.

Airforce (See Table 1 & 2)
The Air Attachés were title-free although Major Lars Hägglöf, whom Captain Sven Cornelius replaced in 1940, had a notable brother.Gunnar Hägglöf was the most important Swedish wartime trade negotiator and a confidant of the Swedish Prime Minister, Per Albin Hansson, and later became Swedish Ambassador to Britain.Major Frank Cervell replaced Cornelius in 1943.
Cervell shared a connection with Olympic competition with Oxenstierna and von Rosen; all were Olympic-level sportsmen.Oxenstierna won the pentathlon gold in 1932, Cervell would go on to win bronze for fencing in 1948 and von Rosen was organising the equestrian Olympics in 1956 when he died tragically.These connections were significant; they could open doors, attract interest, facilitate introductions and networking on an international scale.The addition of an aristocratic, even royal connection further enhanced the opportunities to establish contacts in a class-sensitive country like Britain.As Oxenstierna noted 'Certain very valuable connections have been made through the Prince.'

The Legation
Sweden's London Legation in 1939 was headed by Minister Björn Prytz, previously better known as a successful businessman in the ball-bearing company SKF than in diplomatic circles.An outsider within the Foreign Ministry (Utrikesdepartementet or UD), he networked assiduously but never seems to have been fully recognised or accepted in either London or Stockholm.The same cannot be said for his well-connected service attachés.Prytz was however the head of the Legation and the attachés reported to him as well as to their Stockholm superiors.

Intelligence liaison and attachés
The attachés' British opposite numbers in Stockholm were perhaps appointed more for ability than nobility (or even sporting agility) but they also shared their aptitude for developing relationships.This talent was important for the key attaché remit of intelligence liaison in their host country.Wilhelm Agrell describes liaison as 'a vital element in the intelligence culture, surrounded by ritual secrecy and managed by a selected core of professionals.'4These professionals included the attachés and their intelligence managers.Agrell stresses the importance of making contacts.
In the military field these can encompass anything from cordial social events and well prepared guided tours, to officers attending staff courses and training camps, joint talks at staff level, joint planning and training, standardisation of equipment and so on, all the way to formal more or less binding arrangements for joint operations and mutual defence. . .Liaison, thus, can cover anything from social small talk at a cocktail party and token exchange of garbage information to a permanent all-out intelligence alliance. 5ese contacts are most productive for intelligence if there is mutual trust and trust itself is dependent on perceived competence, benevolence and integrity. 6hus, for attachés, perceptions of competence are based on the attaché's service record; benevolence is evidenced by their approach to sharing information and integrity is signalled by their background and service branch culture.Unsurprisingly then, service attachés' credentials and personalities were vital to their ability to source useful intelligence from their contacts.This explains much about the selection criteria for the Swedish attachés and their performance in wartime London.
Empathetically anglophile, well-travelled international sportsmen with trustworthy upper-class backgrounds and solid service records were the best that a small country could deploy to the imperial capital, to meet its suspicious service chiefs (and their political masters) to extract as much intelligence and cooperation as they could possibly get.Yet before the war began, there was a noticeable tightening of access to information for frustrated attachés.Stig de Berg wrote from London to von Rosen (temporarily in Stockholm on a visit) The possibilities for the military attachés in London to gather such information through official channels . . .appears to be becoming more restricted [. . ..]The new liaison organisation has closed off the potential for direct access to War Office officials [. ..]Personal visits and calls to the liaison officer never leads to results. . .The assistant military attaché concluded that '[. ..] ways other than those mentioned must in future be undertaken more [. ..] a point that I would welcome discussing [. ..] in Stockholm,' that is sourcing information outside of the accepted diplomatic methods.While attaché initiative was highly regarded, there was also an intelligence structure within which the attachés operated in addition to local reporting to Minister Prytz'.

Organisation
In 1937, the three armed services were brought together with a General Staff (Försvarsstaben or Fst) formed to support them.Fst was organised into 10 sections, one of which was intelligence ('U-section').
The Fst chief, a loyal but unimaginative General, Olof Thörnell, appointed Colonel Carlos Adlercreutz to head up and develop the section without specific instructions. 7It was to this section, Fst/U, that the attachés reported and from which their instructions were issued. 8Adlercreutz returned to Finland as Military Attaché in September 1942 to be succeeded briefly by Colonel Carl Björnstierna (a Stockholm intelligence source for British Naval Attaché Denham; exposed and forced out in 1942.)He was succeeded briefly by naval Commander Daniel Landquist then a period under a temporary head, Lt Colonel Gustaf Berggren.In October 1943, former Helsinki Military Attaché, Colonel Curt Kempff became section head under Landquist as department head.The remit of Fst/U had expanded as the war developed, taking on responsibilities for a secret intelligence bureau ('G-Section' becoming 'C-byrån') under the well-travelled Major Carl Petersén. 9Secret and open intelligence sources were now managed, with some friction, within Fst/U. 10 Rivalry and turf wars were a feature of the relationships within Fst/U as well as policy differences as to how neutral Sweden should conduct its interactions with the belligerents.'Kempff detested Petersén, Petersén despised Kempff.' 11 In London, the attachés were overseen by liaison officers in each of the three British armed services.The head of Military Intelligence (Liaison) was Lt-Col.J.D. Carlisle, and the Swedish Military Attaché was the day-to-day responsibility of Maj.A.E. Ker.The Navy's contact point was the Director of Naval Intelligence (DNI) Rear-Admiral John Godfrey then Commodore Rushbrooke.Air Force liaison heads were successively Air Commodores Boyle, Crowe, then Beaumont.Through them, the process by which many of the 'intelligence liaison' contacts such as guided tours were managed by the host country.Official contact was generally regarded as the least productive source of intelligence but it was essential for arranging events such as inspection visits from Sweden or requesting details of weapons, equipment and organisation in response to enquiries from Stockholm.Adlercreutz was stressing the trust element of intelligence liaison although it is hardly likely that the experienced von Rosen would need such basic guidance.Adlercreutz was perhaps seeking evidence that von Rosen's official requests were being ignored so that pressure could be applied at a higher level.The attachés produced three types of written report for Stockholm; reports, memoranda and so-called hand-letters for sensitive intelligence (handbrev) which were not usually circulated.Reports were sent to the Ministry of Defence following review by Minister Prytz.Memos and hand-letters went directly to the Fst/U head but these could be copied also to relevant service chiefs and, via the Foreign Ministry, to politicians.This sensitive overlap was to create issues regarding who was told what and when.Prytz did not share much with his own diplomatic staff and even less with the attachés. 13verviews of the military situation were sent as reports while political assessments and personal comments were reserved for hand-letters. 14Above these tedious but essential bureaucratic processes, security of the intelligence, the sources and viewpoints contained in the reports was paramount for both political and military reasons -as later events were to show.

Reporting and processing
The intelligence contained in attachés' reporting was transmitted onward to the appropriate service branches by Fst/U depending on Fst/U's assessment of the relevance of the content.Fst/U head also prepared a periodic 'Commanders' briefing' (Chefsorientering) which was circulated to over 20 senior officers in all three services as well as the Cabinet Secretary.Intelligence from attachés could contribute to that briefing which, via the Cabinet Secretary, could also reach the Swedish political leadership.

Distractions from intelligence gathering
The overall effectiveness of intelligence gathering and reporting was affected by three activities that were nevertheless integral to the role of the service attaché: • Representation of Swedish interests • Procurement and supply from Britain • Personnel matters Unfortunately, these extremely diverse activities cannot be expanded on here due to space constraints, but it is clear from the archives that they formed a variable but constant distraction and an additional heavy workload away from intelligence duties throughout the war for the attachés.

Finland's Winter War -logistics liaison and policy problems
In August 1939, Sweden's military attention was directed east to the Soviet threat in the Baltic following the shock news of the Molotov-Ribbentrop Pact and London was not at the forefront of Stockholm's attention.Military Attaché von Rosen left for Stockholm just before the Winter War and remained in Fst/U until 1940 while his new assistant, Carlbom filled his London role at this critical period.
With the common aim of supporting Finland against the Soviet Union, the offer of British material and manpower between December 1939 and March 1940 led to British-Swedish military cooperation involving the attachés while paradoxically, the British-French attempt to use the Winter War as a cover to seize Swedish iron ore mines created major political disagreements.This was a welcome change from the peacetime attaché activities of clipping out articles from newspapers for Stockholm and accepting invitations to visit military facilities.It was useful that Von Rosen had previously met his British counterpart in Stockholm, Military Attaché Lt. Col. Sutton-Pratt while both served as observers for the Saar Plebiscite in 1934-5.There now followed a period of intense activity by Britain to; recruit, train and send British intelligence officers to Finland; source, supply and deliver weapons and equipment; and provide technical and medical support to the Finns.The Legation's attachés provided essential contact points.British-Swedish liaison was on a war footing with the attachés involved in many of the arrangements.
The supply of assistance to Finland was a sensitive subject in Berlin because it was seen as creating difficulties between Russia and Germany.Minister Prytz had already been reprimanded by Stockholm for inadvertent disclosure.15

Scandinavian occupation and Swedish subservience
The 9 April 1940 invasion of Denmark and Norway was a triumph in springtime for Hitler and Germany as well as a blow for Sweden and her London attachés.The fragile, special Swedish-British military liaison that had operated during the Winter War was now replaced by a tense and suspicious relationship.The London Legation was increasingly isolated while Stockholm's attention was abruptly turned from the traditional Russian enemy in the east to the new and previously underestimated German threat to the west and south.
The symbolic concession of transit by rail for German troops in occupied Norway on leave through Sweden combined with continued trade in iron ore to Germany, signalled an inclination to appease the Germans. 16hat inevitably affected British trust in the Legation's attachés at a time when their reporting was more important than ever to Fst/U.Paradoxically, Sweden and Britain again shared the same immediate enemy, this time Germany and not Russia, but the stranglehold by Germany and Swedish fears of a German victory in Europe meant that the Swedes played both sides pending an uncertain outcome.In the meantime, they urgently required to rearm and retrain to prepare militarily for an immediate German attack and a possible later Russian incursion.
From 1940, Britain was a vital source of information for development of both modern weaponry and effective organisation and the attachés were now vital to that intelligence.It was also in the British interest to support strengthening Swedish defence against German attack.However, could the British trust that intelligence would not leak to the Germans and that Swedish weaponry would not be seized or given to the Germans in the event of occupation?The issue of trust in the relationship now came to the fore in mid-1940, ebbing and flowing until the end of the war to vary the effectiveness of intelligence gathering by the attachés.

Intelligence specification
There is a recurrent issue of intelligence specification evident in the correspondence between London and Stockholm.The attachés' requests for guidance as to what the services in Stockholm required is an indication of an expectation in Stockholm that the attaché was to a great extent self-directed and ought to know what to gather and report.The procedures for reporting had been laid out in 1937-8 in four instructions but evidently these were proving inadequate.Naval Attaché Oxenstierna wrote in 1942 that '. . . it is of the greatest value to learn how the memos, reports etc. are regarded.'He had earlier asked to be told if any of his reporting was '[. ..] unclear, contradictory, incorrect or incomplete [. ..]' Fst/U's Kempff set four points for guidance to Military Attaché von Essen in November 1943; a) news cuttings on politics are of little use, but send reports on b) current fighting, particularly tactics and technical details; c) photos, particularly combat and technical; d) personal impressions of mood and situation.
However, as the war progressed, there were more frequent requests from service branches for increasingly specific information which had to be restrained for fear of upsetting the British authorities.These are reviewed in more detail later.

Overt intelligence
Overt gathering of service intelligence by the attachés was limited by their British services liaison as noted earlier.They also had to operate in a hostile environment.As early as September 1939, von Essen was told that any journey made through a military area had to be approved in advance and even a visit to the Port of London was refused in October 1942.
Assistant Military Attaché Carlbom reported in an undated extract (probably January 1941) that The liaison officers in the War Office are endeavouring that the Swedish attachés in London get to see and experience more.From 'private sources' it has emerged that in 'official' circles, certain members of the Swedish Legation harbour views that are not sympathetic to England.
This may refer to Naval Attaché Wesström's somewhat pessimistic views about British performance expressed when on leave in Stockholm.Such views affected the liaison relationship to Sweden's detriment as von Essen complained to Stockholm. 17owever, there was an easing of the relationship in 1942 after Denham, the British Naval Attaché in Stockholm, urged the Admiralty to invite the new head of Fst/U, Landquist, to visit Britain in early 1943.There were risks as well as opportunities from enemy contact because Landquist had already visited his opposite number in Finland, Aladar Paasonen in November 1942 and Abwehr Chief Canaris in Germany in December.Oxenstierna was asked to facilitate the visit dates and Denham's memoirs deemed the visit 'a great success' providing a return to a more cooperative relationship. 18ritish caution may have eased but remained.The Director of Naval Intelligence, Rushbrooke wrote to Denham, in 1943 that [. ..] you express the opinion that intelligence is not passed to the Germans.This is a complete surprise.It must always be assumed that information given to, or obtained by, the Swedes will reach Germany, and we have very good reason to know that this does in fact occur. 19is last point is a reference to a Swedish security failure discussed later but goes a long way to explain the barriers placed around the attachés' access to useful information.

Covert intelligence and issues in Stockholm
Covert gathering of intelligence by the attachés was of course risky because of the danger that suspicions already held by the British establishment might be confirmed by 'activities incompatible with their status as members of a diplomatic mission' and lead to withdrawal of access to official sources or even expulsion.
Naval Attaché Oxenstierna highlighted the grey area between overt and covert intelligence gathering when in May 1942, he reported to Chief of the Navy, Admiral Tamm, that the British navy periodically circulated two secret intelligence reports; one to senior officers regarding recent operational experience; the other to all officers containing less detail.Oxenstierna had been allowed to read some of these '[. ..] with the promise "not to be reported home."''One or two things of value could be gleaned from them.'He then went on to outline his fears that if he reported this back to Stockholm and they were traced to him, that would end confidential briefings from the British.He next pointed out that the wide circulation of reports in Stockholm was 'risky' and that he had suggested to Fst/U's Björnstjerna that such reports be sent direct to him for limited circulation only to those addressed by Oxenstierna.When he had written to Björnstjerna, Oxenstierna had also asked him to tell Denham that circulation of his reports from London had been tightened in Stockholm so that a reassuring message would get back to the Admiralty in London.In October 1942 Björnstjerna wrote outlining some of the circulation changes due to Fst/U reorganisation.He emphasised that although technical matters could be circulated to other services, '[. ..] it was absolutely not for political or strategic matters.'And that Wesström should not send 'extra reports' to his Admiral.For intelligence of particular importance, that should be addressed personally to Björnstjerna marked 'strictly confidential', 'Personal', or 'Only for the inner circle.' Later that October, Oxenstierna wrote to the new Fst/U head Landquist again outlining his security concerns regarding handling of intelligence sourced by him in Britain and urging that the circulation procedures be reviewed.He claimed that he was more effective than the other attachés because he had a direct reporting line to a senior naval officer, C.J.A. Skarin, who could assess and distribute intelligence accurately and swiftly, thereby avoiding the bureaucratic delays in the current process.
Military Attaché von Rosen envied Oxenstierna's direct line to Skarin who also provided essential feedback on the value of Oxenstierna's reports.For example, Skarin told Oxenstierna that his reporting on convoys and U-boats was greatly appreciated.However, in November, Fst/U's Berggren (citing Landquist's support) firmly rejected Oxenstierna's direct reporting proposals ('counter to purpose') in favour of wider circulation while claiming his long experience as an attaché (actually only five years in Moscow) enabled him to deal with all services' intelligence and that Fst/U's '[. ..] most important task [was] to coordinate the different services' activity and thereby prevent unnecessary duplication.'He was probably reflecting a concern that silos of intelligence prevented useful information being made available to less obvious recipients.He cited the example of naval anti-aircraft measures being of use to all the services and reminded Oxenstierna of the three forms of attaché reporting to Stockholm and what content should be in each.Oxenstierna replied compliantly and pointed out that collaboration between the Legation attachés was good.
Yet, as mentioned above, one of Oxenstierna's 'hand-letters' ended up with the Prime Minister Per Albin Hansson in December 1942 without the short-fused Defence Minister Sköld's knowledge.Rear-Admiral Giron told Oxenstierna that another Minister (Statsråd) had in effect overruled Björnstierna by directing that in future, reports of this type should be sent directly to Giron who would then inform the Minister.'This has always happened in Berlin and works well [. ..] not through Fst, which is an unnecessary delay.'When Kempff took over from Berggren in late 1943, he asked Oxenstierna to write to him informally and directly if the source or intelligence was questionable without copying Fst/U.When Prince Bertil took over from Oxenstierna, Kempff repeated that instruction.
This double disregard for Berggren's instruction may have been behind Oxenstierna returning to the subject of report circulation.When in May 1943, Oxenstierna reported his opinion to a senior officer on British experience of the best calibre for anti-aircraft guns for warships, he added that he needed to be called back to Stockholm '[. ..] to clear up a number of such questions, if that is to be done systematically and effectively, can only be done orally [. ..]' (his underline) It is ironic that later in 1943, it was a German source in Fst/U that led to Oxenstierna being recalled.
What these exchanges reveal is the conflict between the attachés' attempts to limit the circulation of London reports to protect their position of trust and maintain their intelligence sources and the understandable desire by Fst/U to assess the relevance of the intelligence for selected recipients and to ensure that useful information reached the correct individuals and branches.They also reveal the security limitations of written reporting, whether by code or diplomatic bag; some intelligence was too sensitive and the principle 'nothing on paper' meant oral reporting in Stockholm of which no record is available to research. 20This also applied to the Military Attaché in Berlin, Juhlin-Dannfelt who with easier travel connections visited Stockholm a couple of times annually and briefed his superiors orally.21

Contingent intelligence
Contingent intelligence gathering was the third method used by the attachés which encompasses the activities that Agrell categorises as intelligence liaison.In this grey area between the black and white of overt and covert gathering, diplomatic status provided the attachés with access to civilians and service personnel from whom they could derive unofficial information.
Fst/U's Kempff suggested, in the face of restricted War Office briefing, 'was it not possible to get information in other ways' such as 'in the Club in discussion with other attachés.'This extended also to information that could be picked up during official visits and tours organised by their British service liaison.Nuggets, snippets and hints could be unearthed in more casual conversations but there were risks.

British deception
In late 1942, British counter-intelligence agency MI5's Colonel Bevan proposed that neutral diplomats should be used for deception purposes.After having set out the types of intelligence likely to be sought by a neutral '[. ..] military strength, organisation, disposition and intentions', the proposal notes that 'Details thus obtained are [. ..] known in many instances to be passed to the enemy.'The proposal instances that some of the neutral officials gained '[. ..] fairly accurate knowledge of our North African plans and intentions.The problem arises as to how we can try to prevent a recurrence in the future.'Churchill himself was 'much disturbed at the amount of Torch information' apparently leaked.Bevan's proposal was to supply British officials with deceptive narratives which '[. ..] should contain mostly truth but be presented in such a manner that a false conclusion might be drawn by the hearer.'One such objective was 'To indicate an invasion of north Norway.'While Swedish officials became increasingly alert to potential deception, the proposal, although at this stage rejected by Foreign Minister Eden, confirms that they were considered targets by the Allies using 'Suggestions for Dinner Table Talk' to mislead the Germans. 22So for the attachés, official channels were restricted, and unofficial channels were suspect.

Sweden-Britain communication and London security procedures
Following the German occupation of Norway and Denmark in April 1940, the courier service which carried most of the attachés' correspondence was suddenly interrupted by the virtual blockade of Sweden from the west.Alternative routing, for example via Lisbon in Portugal or via Petsamo in Finland, took time to arrange and in the interim, correspondence and reports went astray.Even in January 1940, Assistant Military Attaché Carlbom reported that 'The courier service is bad, and I have not heard anything from you for six weeks.' In May 1943, Naval Attaché Oxenstierna was advised by a signal from Stockholm that there would be no courier service for the next four to six weeks.The Legation's diplomatic telegram and radio links could of course be used but only when there was spare capacity.As a result of the German invasion of Norway and Denmark in April 1940, Naval Attaché Wesström advised Stockholm that Minister Prytz had ordered that for heightened security, all cipher communication had to go through the UD's communication system.Fst/U's Adlercreutz had assured Military Attaché von Rosen in August 1940 that the Stockholm cipher experts had judged the Legation coding machine to be secure and to be used as required while other methods were insecure.Also, the unreliability of surface mail meant that telegraph was more appropriate.Prytz' confidence was misplaced.The Legation was unaware that by 1939, the British had broken the Swedish diplomatic code and a famous telegram sent to Stockholm in 1940 by Prytz after his meeting with R.A. Butler '[. ..] written in the special code and marked strictly confidential [. ..]' was on Churchill's desk shortly after dispatch. 23The so-called 1940 'Prytz Telegram' implied that there was a faction in the British Government that was prepared to negotiate with the Germans and remove Churchill.] 24here was sensitivity over the handling of information that could be considered 'military' and in 1941, Carlbom complained to Rosen that attachés were unhappy about such information going direct from the Legation to UD without their knowledge.Surprisingly, he also raised this with the War Office to emphasise that the attachés were the preferred conduit for military information to Sweden and not the diplomatic 22 NA CAB 154/32 Neutral Diplomats and Attachés. 23Fritz, Vår man i London, p.180.IWM 11,946 Tennant, Peter (Oral history) Reel 1. 24 For a full and excellent account of this incident, see Fritz, Vår man i London, pp.169-98.
representatives.He reported 'If this situation continued, it was possible that (Swedish) services representation in London would be withdrawn.' As the war progressed, the establishment of a reliable Britain-Sweden airlink provided better communication for the attachés using the courier service.However, even here, there were British suspicions that the Germans had somehow been able to intercept Swedish attaché reports. 25

Stockholm security lapses
The attachés were rightly concerned about the security of their reports when they were circulated in Stockholm.Air Attaché Cervell and Naval Attaché Oxenstierna were the victims of British suspicions that they were the source of sensitive information acquired by the Germans.This was in fact the case but neither were aware that their intelligence reports from London were being copied in Stockholm by women secretaries in Fst/U for Carl Heinz Krämer, an Abwehr Lieutenant-Colonel in the German Legation. 26Their subsequent transmission to Germany had been intercepted by British SIGINT who were able to compare the information with the Swedish attachés' diplomatic intercepts and thereby accurately identify the sources. 27he incidents resulted in Oxenstierna being recalled and Cervell being advised by his superior to limit the scope of his enquiries to, '[. ..] tactics and technics [. ..]' 28 The baffled Oxenstierna was replaced by the far less effective but well-connected Prince Bertil.In the Legation, security was observed and von Essen was told that an internal investigation showed that Oxenstierna had 'behaved correctly and to state that Oxenstierna had been transferred back to take up a ship command in the Navy.'  The attachés and Stockholm had to adapt continually to the problems created by wartime communication difficulties and continually observe security procedures.When security failed, it had drastic consequences for the attachés as in the removal of Oxenstierna and could create major problems for Sweden's position.
In the following sections, a selection from the extensive range and content of Attaché reports is reviewed in five broad categories, none of which are mutually exclusive, to provide an overview of the material which was sourced in Britain and reported to Stockholm.
• Strategic • Tactical • Technological • Combat methods and weaponry • Organization and training These selected reports are not reviewed in strict chronological order because their importance and content were more dependent on the expertise, interests, and access to sources for the author than the date of writing.There is however an evident increase in specific instructions from Stockholm regarding intelligence required as the pace of Swedish rearmament increased.

Strategic assessments
During the course of the war, in sharp contrast to what MI5's Bevan believed when considering deception, Swedish attaché reporting from London became much more focused on intelligence that the services could use to enhance training and rearmament.There was diminishing interest in the attachés' opinions of how the war was developing and increased requests for intelligence on specific topics.Political and foreign policy reporting was discouraged for two reasons; firstly, this was a subject for the diplomats and secondly, the Swedish government strived to keep the armed services out of foreign policy.Carlbom's 1939-40 reports to von Rosen (who was temporarily in Stockholm) are notable for their freeform coverage of a multitude of topics.Such range is notably absent from later reports -as was easy access later to British information.
In addition, Fst/U could also source more up-to-date intelligence about German and Finnish strategy from the Military Attachés in Berlin and Helsinki.Juhlin-Dannfelt's German connections and those of Kempff (before he became head of Fst/U) in Helsinki were much more valuable to the Swedish military and political leadership, partly due to their access to authoritative sources and partly because they related to the shared threat from the Russians.London was somewhat relegated to a secondary role for intelligence related to what has been described as '[. ..] the primary task for the intelligence function [. ..] to detect any signs of German (or other) preparation for hostile action toward Sweden.' 29 In the west, alive with rumours of German preparations in March 1940, Adlercreutz asked von Rosen in March 1940 to try to get more specific information about these stories when next meeting the Director of Military Intelligence.Adlercreutz thought that these actions were directed against Holland or Belgium and does not seem to have considered Scandinavia until the beginning of April when attaché intelligence from Helsinki and Berlin indicated otherwise. 30ollowing the beginning of the German 1940 offensive, Wesström advised Stockholm that the situation reports he was getting from the Admiralty were due to his guarantee that these would only be shared with Prytz personally and then seen only by the coding clerk when sending to Stockholm.
After the invasion of Norway and Denmark, Adlercreutz criticised von Rosen's recent 1940 reports as being too similar to 'the general information emanating from the Legation' and encouraged him to provide intelligence that the services could use.
Carlbom's somewhat wordy assessments were clearly noticed and an undated but attributed Fst/U summary for circulation in Sweden (probably December 1940) notes that 'In the War Office, they regard an invasion as now rather unlikely and believe that the Germans will attempt determination by war at sea.' In another example in December 1941, he recounts his briefing in the War Office by the liaison officer and his seven-page report includes military assessments on Libya (optimistic), Russia (German retreat), Far East (serious), Philippines (Japanese concentrating on Malaya) and he cross-refers to other discussions with Russians, Americans and 'a private source.'He noted that the War Office's Military Liaison Head, Carlisle, was 'clearly most receptive' in an 'atmosphere of optimism' and had suggested future weekly visits would be 'a good idea.'These comments, only ten days after Pearl Harbor, perhaps indicate a conscious Allied attempt to send, via Sweden, a message of defiance to Germany and her ally, Japan.The Swedish attaché back-channel was useful to London.
A reliable source had assured Oxenstierna that a large, combined Allied operation was planned for Norway on 10 December 1942 and he added his view that it was likely.This was directly contradicted by von Essen in a report (delayed in transit by seven weeks) that no invasion of Norway would happen until German troop reductions could attract the Soviet Union to seize North Norway and an Allied invasion would deter the Russians.Oxenstierna's alert went astray in Stockholm and created an explosion in Cabinet when Prime Minister Per Albin Hansson raised it and Defence minister Sköld knew nothing about it.
By 1943, Kempff was asking for answers to questions such as 'Can aircraft production, particularly heavy bombers, keep up with losses' and in this connection had the 'quantitative and qualitative' level of aircrew had decreased?
Crucial to Swedish assessments of progress of the strategically vital battle of the Atlantic were merchant shipping losses and replacement production reported by Oxenstierna in 1943 in a detailed report with graphs '[. ..] from confidential sources [. ..]'.
von Essen was more inclined to present his 'private thoughts' on strategy.In August 1943, he confidently predicted that there would be no Nordic invasion that summer.
von Essen later reported to Kempff in October 1943 on strategic concerns to be forwarded to the Commander in Chief.These concerns included fears in British military circles about the Soviet threat to Scandinavia as well as Britain, his belief that there remained a British view that Germany would still be needed to counter that threat, the rejection by Norwegians of a Scandinavian alliance and to instead rely on the Western Allies (including his view that the four Nordic countries should standardise all military equipment) and finally the British belief that bombing would lead to a German collapse.
One clear strategic message that was delivered from London to Stockholm was that of early British determination to persist with a resolve to win against Germany, fuelling high morale despite reverses and bombing.To von Rosen, Adlercreutz characterised the historical significance of the dire British position in 1940 as comparable to '1588, 1648 or 1789.' Yet Adlercreutz rebuked Wesström for being influenced by Swedish colleagues to report 'optimistically' and insisting on 'objectivity' in his reporting.
Newspaper clippings on the war situation were of little use in Stockholm.Kempff made it clear that such reports on the political situation' were of 'limited interest' not least due to their content being quickly outdated.However, reports on the military situation, particularly regarding 'tactical and technical' were eagerly sought after.Following D-Day, Naval Attaché Bertil was asked to provide details of the landings and naval factors such as weather and tides.
Understandably, any report that dealt with direct threats to Swedish territorial security received close scrutiny but in general, Fst/U does not seem to have been the preferred source for government assessments of the overall direction of the war.The UD's more senior connections in the belligerents' capital cities provided those instead but they could be qualified or enhanced by attaché comment.

Tactical assessments
British 'tactical and technical' intelligence was perhaps the more valuable to Sweden and the most problematic to gather due to its obvious potential for use by an enemy.This did not deter the attachés or their services in Stockholm from attempting to access it overtly.
Although British land forces were not engaged in northern Europe between Dunkirk and D-day excepting Dieppe, the Swedish army, lacking any operational engagement as a defensive neutral, nevertheless wanted to learn about all tactical developments.
A sample of requests from Stockholm included the following.In anti-aircraft engagements, 'Methods for carpet barrage.Experience from carpet barrages.'In January 1944, regarding the German air-raid on London, 'Number of attacking planes, flight height and tactics.'Mid 1944, 'Allied fleet losses and damage from the invasion of France.' From D-day, seven naval questions including 'Ship artillery's role during the landings.'In October 1944, the impact of new German fighters in the west and 'what measures and steps' are being taken or considered.
The enthusiasm with which the services increasingly bombarded the attachés with requests worried Kempff to the extent that he wrote to Bertil in late summer 1944 about the potential counterproductive effect of services' 'wish-listing'.
One must remember that Britain is a country that, with great sacrifice, fought hard for its national existence and here as in other fighting countries, all measures must be taken that no important military intelligence comes to the knowledge of the opposition.[.] However desirable [.] to receive a correct account of the current situation, intelligence gathering in this area however must stand behind the necessity to behave responsibly and unobtrusively in all regards.A service attaché also ought not to, even through innocent questionsofficially or unofficially -touch upon important operational questions for the fighting country.One only thereby raises suspicion and as a result misunderstanding and in the end suppression of the whole approach.
Oxenstierna's forward approach that so disturbed the British ('[. ..] rather resented his extreme inquisitiveness [. ..] he misses NOTHING (sic) [. ..]') had cast a long shadow over the Legation and in this, Kempff's opinion matched the British view. 31'He (Oxenstierna) was also more than assiduous in seeking information and intelligence [. ..] extended to individuals within the Admiralty [. ..] all in close touch with Operational Intelligence.' 32 The Catch-22 for the attachés was that the more successful tactical intelligence gathering was, the more it impinged on operational sensitivities leading to problems for Swedish intelligence liaison.Yet, the results were appreciated in Stockholm.For example, Oxenstierna was told that a 1942 tactical report was particularly useful for 'convoy duty and U-boat countermeasures.'Intelligence liaison in its social form also could benefit tactical intelligence.Denham's assistant attaché, Dan Gibson-Harris wrote from Stockholm (in Swedish) to Oxenstierna in December 1942 to tell him that '[. ..] we have got permission for the Swedish authorities to get copies of the secret training films "Eye Shooting and Tracer"' and to ask the Admiralty for other training films on minesweeping.In exchange, the British got a film about the armed Swedish Baltic icebreaker, Ymer.
The overt tactical intelligence gathering method of visits to establishments, exercises and after D-day, battlefields was fully exploited by the attachés but with mixed results.The British could be frugal in their invitations and access to information during the visits.Nevertheless, after von Essen arrived in August 1942, six visits were arranged for him.
• Battle School (sic); Report No. 5.While these visits were carefully managed, tactical intelligence was evidently collected and reported.von Essen told Kempff to pass on his observations on tanks and artillery fire-direction gathered during his Larkhill visit.But as the British position strengthened after Stalingrad and while Swedish cooperation with the British Military Attaché in Stockholm remained limited, further restrictions were imposed.In fact, he was only given two visits in the whole of 1943.The message was clear; provide more intelligence or you will get nothing from us.
Tank warfare remained high on the agenda of tactical intelligence sought as a 17point list of questions sent to Lundberg e.g.'14.Views on use of armoured vehicles in attacking fixed positions organised for strong defence against tanks?How are armoured vehicles used to attack and break-through?Direct support by infantry?von Essen and Lundberg sent a considered critique of tank and armoured vehicle strengths and weaknesses based fully on British tactical experience to guide Swedish development.In December 1943 when he requested another visit to a tank regiment, he was told that '[. ..] there was no great prospect for us for there was too much equipment that was still on the secret list.' Equipment was high on the attachés list of intelligence priorities.

Technology developments
Swedish forces' research effort was focused on the areas of: • Gas protection and development This focus was often reflected in the requests for technical intelligence from Stockholm.The technological advances in military equipment were key to Swedish rearmament efforts but in this area, Britain was careful to restrict access to both suppliers and technology.It was also when seeking technological intelligence that the attachés became the centre of British suspicions.The three services were keen to access this intelligence and the attachés devoted much effort to overcoming obstacles and gathering it.
Development in radio communication was a key area for intelligence gathering and associated with that were developments in message encryption.In July 1940, perhaps as a move to support Sweden against German invasion, the Admiralty shared German coding practices with Wesström.Even more surprisingly at the same time, Wesström appears to have been given details (including deciphering) of how the British navy used their codebook with the 'false substitution technique' that he reported with the comment that it was '[. ..] practical and easy to use.' British radio communication developments remained a key target for Stockholm, particularly for the air force.In 1944, Cervell got a 10-point enquiry from Kempff covering both technology and practice for example the use of LW, SW, Ultra SW, transportable and portable equipment.Kempff noted the likely sensitivity of some of these questions.
Radar was of particular interest and in April 1942, Oxenstierna was asked to get intelligence on 'dimensions, installation, antenna system and dimensions with wavelength range.' 'You ought also to seek permission to get on board a destroyer to get a closer look at such an installation.'Stockholm even recommended that he approachRobert Renwick who was instrumental in establishing Britain's radar defences. 34'A corresponding shore installation is also naturally of interest.'The instruction was followed up by even more detailed questions with the admonition to '. . .get answers as soon as possible.'This is significant for four reasons.Firstly, the instruction came directly from Oxenstierna's naval contact, Skarin, through its command structure and not through Fst/U.Secondly, it demonstrated a remarkable naivety about the importance of this technology to the British.Thirdly, by approaching a civilian on this subject, Sweden risked not only raising suspicions but also creating major diplomatic difficulties as later occurred.Finally, with the 1942 reference to Russian submarines in the Baltic, it is clear that the Swedish navy was in direct conflict with Britain's ally, confirmed by the torpedoing of a Swedish ore-carrier headed for Germany in August and Skarin's comment that '[. ..] your reports will be immediately put into practice.' Other technologies of interest to the navy in 1942 were mines, acoustic and magnetic.In 1943, the Navy's interest was stabilisation equipment and acoustic/magnetic torpedoes.Oxenstierna reported in March 1943 that while stabilisers improved naval artillery accuracy, they reduced operational range due to the space occupied could not be used for fuel tanks.In any case, Oxenstierna was refused design details by the Scottish manufacturers 'unless we are directed [. ..] by the Admiralty.' Oxenstierna reported in May 1943 on degaussing and on the Vickers anti-aircraft pom-pom concluding that the Bofors 40 mm weapon was superior.He provided a report in August with sketches on depth charge equipment and tactics based on his visit to a modern British N-class destroyer Piorun in Polish service.A further report after a visit to inspect Vosper's latest MTB in October generated detailed technical questions from a naval specialist.Stockholm's demand for equipment detail was continuous and growing.Another report detailed the use of Stirling bombers for mining the seas off France following a visit to an airfield.
Earlier in July 1942 in an example of inter-service cooperation, Cornelius sent Oxenstierna an extremely thorough British report with experimental results of the behaviour of aircraft-delivered torpedoes under different conditions which could reduce their targeting accuracy.He added that due to the secret nature of the subject, it should only be distributed to named individuals '. . .according to the "Oxenstierna" method.' (sic) reflecting Oxenstierna's concerns to prevent intelligence reaching the Germans or the British discovering that the intelligence had reached Sweden from London.
Although this current research does not aim to demonstrate a direct link between the technology intelligence gained from the London attachés and Swedish wartime weapons development and production, it is inconceivable that none of it was utilised for the Swedish effort when the scale of output is considered.Between 1939 and 1945, a few sample production statistics (Table 3) are relevant:

Combat methods and use of weaponry
Carlbom reported in January 1942 that he had pressed the War Office's Military Liaison Head, Carlisle, for military visits, particularly to mechanised manoeuvres, or coastal defences, a full year after Carlisle had promised more.The coastal defence visit took place but was deemed '[. ..] interesting but nothing particular to report [. ..]In August 1942, von Rosen was sent an advance copy of the British assessment of the campaigns in Greece and Crete but sharing of such information was the exception.
In December 1942, von Essen tried to get information on the use of aircraft to guide artillery fire.Carlisle's response to the nine questions was one sparse line per point, for example, 'As regards planes for observation and communication, we have no remarks.'attachés.This invitation was perhaps behind another Fst/U request to provide details of Allied post-invasion logistics and communications in a range of questions from railway capacity to right-or left-hand driving.There were clearly sensitivities regarding the organisational implications of attachés' reports.With the end of war in sight in October 1944, von Essen and Lundberg drew on their experience of warfare development in Britain and set out their thoughts on the future of warfare on land, at sea, and in the air that had changed with the introduction of the jet engine, rocket missiles, paratroops, and civilian targets.This drew a withering response from Kempff in Stockholm who claimed to be reflecting the view of the Chief of Staff.
If our organisation needs change, our officers will do it on the basis of considerations which must be more deeply founded than experiences solely from a London perspective. ..I hope that you don't misunderstand me.We'll draw the conclusions ourselves.
The effect of this demotivating rebuff can only be guessed but the message was clear -do not exceed your remit -which put attachés in the invidious position of always being open to criticism for either reporting in too much or too little detail.

Military organisation, training, and deployment
As the Swedish services modernised their equipment, the leadership was also interested in the latest approaches to the belligerents' fighting organisation, training, and deployment as these were being tested in actual combat which neutral Sweden could not experience.The range of interests from the various service branches reached the attachés in the form of requests for visits, manuals and reports.
Earlier in January 1942, Carlbom arranged a visit to British coastal defences in Clacton where he saw at first hand the installations and weaponry there, but the attachés had found it difficult to get useful information from the British in the early stages of the war.However, there was an apparent initiative to ease access later in January 1942 when the War Office's Military Liaison Head, Carlisle, hinted that Carlbom might be permitted to visit a motorised unit to observe exercises and equipment if Sutton-Pratt in Stockholm was given more information about the recent Swedish army reorganisation.The same week, Cornelius and Carlbom were allowed by the Air Ministry to visit an anti-aircraft site at Stanmore.Reciprocity was evidently a major factor in these discussions.However, Carlbom reported that '[. ..] we did not get to see anything of interest and only spoke to the Intelligence Officer.' As well as visits to training establishments, the British also provided copies of organisation and training material to the attachés; for example, the Organisation of the British Infantry Division (market 'secret' by Carlisle in his covering letter) in September 1942 and an Artillery Training Pamphlet in December 1942.
In October 1942, von Essen received a 10-point general questionnaire from the head of air defence that included organisation and deployment.It must have often appeared to the attachés that the demand for information was insatiable.von Essen was even asked in November 1942 to find out how the British services were organising and using psychological testing in recruitment and allocation of manpower.In December 1942, von Essen's report on the British 'Home Guard' was not only appreciated in Stockholm but also triggered a further list of questions covering seven subjects such as recruitment, organisation, and discipline.
In January 1943, Carlbom was asked to arrange for a 'study visit' from an anti-aircraft specialist and three members of the women's volunteer corps (known as 'Lottas') to find out how women were being used in air defence.This was refused by Carlisle in April citing required limitations thus rendering '[. ..] their tour of doubtful use [. ..]' In July 1943 Oxenstierna asked the Admiralty for information on recruitment, training drafting, promotion and retirement of non-commissioned ratings.
One wish-list of over 14 naval questions in July 1944 covered everything from Admiralty organisation to the latest sonar range for detecting U-boats was sent to London by-passing Fst/U.It points to the release of pent-up demand from Stockholm after a long period of restriction targeting now urgent technical intelligence.

Conclusions
Regarding the overall value to Sweden of the attachés' reporting, it is perhaps relevant to note here that their efforts were not always appreciated.In the UD the most senior official (Boheman) noted dismissively to Prytz in 1944 that '[. ..] the reporting by our military [attachés] has been of the sort that, as far as I can judge, no intelligence of real interest has been received.' 38erhaps the most important area of the attachés' intelligence gathering was linked to the development of the defence capability of Sweden, a benefit not fully appreciated in the UD by senior figures like Boheman.Swedish services encouraged attachés to acquire intelligence about important British secret technologies and tactics.It is clear from the archives that the attachés delivered an amazing volume and range of very detailed technical intelligence that might have surprised their British service liaison officers had they known.Oxenstierna, for instance, demonstrated a phenomenal memory which, alongside his skill as a draughtsman, produced some impressively detailed reports prior to his recall.
Reciprocity mattered.The attachés service liaison relationships in London reflected the relationships experienced by their British opposite numbers in Stockholm.The British services were initially cooperative with the attachés until Sweden flexed neutrality towards the Germans between mid-1940 until early 1943.During this period, the Swedish government retained German-friendly (but not necessarily Nazi-sympathising) officers in key service roles and scrupulously avoided favouring the Allies.Meanwhile, the British services did their best to keep the Swedish attachés 'on-side' knowing that the Germans were attempting to achieve sympathy in the Swedish services for their 'crusade against bolshevism.'When the Western Allies re-asserted their dominant position in providing opportunities for intelligence gathering, they restricted access until Sweden relaxed its restrictive practices and 'opened up.' Fst/U's Adlercreutz advised Military Attaché von Rosen in early March 1940 I do not know in greater detail how you interact with your English (sic) contacts.When you only officially visit them and do not get your requirements met, I ought to get definite reports of what you requested and what is refused.It is also really important to tackle them, so as to say, more personally over a meal and in that way get them to understand that in you, they have a personal friend etc.