In 1939 with Europe on the brink of war, a British agent named Ingram Fraser smuggled a considerable quantity of high explosives into neutral Sweden in the diplomatic bag.
It was stored in a cellar at the British Embassy in Stockholm for use in Operation Strike Ox, a daring scheme to disrupt Swedish iron exports to Germany by raiding the Swedish east coast port of Oxelosund. Clearly the operation would have violated Swedish neutrality.
But the real aim of the raid was still more devious, according to a newly published book that has resurrected the affair to the embarrassment of both British and Swedish authorities.
Thomas Munch-Petersen of University College, London, claims in his book ''The Strategy of Phoney War - Britain, Sweden and the Iron Ore Question 1939-1940,'' that Strike Ox was planned by Winston Churchill and Sir William Stephenson, head of British Security Coordination, in a bid to get Sweden into the war on the side of the Allies.
British thinking, Dr. Munch-Petersen says, was that Germany would be forced to invade Sweden to secure the iron ore shipments so vital for its armaments industry, and that Sweden would be obliged to retaliate.
Dr. Munch-Petersen says: ''It was clearly an Allied interest to involve Sweden in the war against Germany and this was the main purpose of British policy toward Sweden during the Norwegian campaign. The British authorities realized that the Swedish government would not enter the war voluntarily and that the only way of obtaining Sweden as an ally was through a German attack on that country.''
In the end Operation Strike Ox proved a fiasco, ending with the arrest of two Britons, a German dissident socialist, and a young Swedish woman.
The following account is reconstructed from Dr. Munch-Petersen's book and the transcript from the trial of the four conspirators, now declassified and available for examination at the Stockholm city archives.
The story begins with a communique from Stephenson, under his codename Intrepid, to Winston Churchill, then First Lord of the Admiralty. Stephenson said a large supply of iron ore had been accumulated at Oxelosund, 60 miles south of Stockholm, for shipment to Germany after the port of Lulea in the far north had become ice-bound.
Stephenson suggested that Oxelosund be sabotaged and offered to set up the operation. Churchill agreed.
While Ingram smuggled in the explosives, Alfred Frederick Rickman, a British businessman living in Stockholm, was recruited to carry out the raid, which was to involve blowing up the dockside cranes at Oxelosund.
Rickman was a colorful character, a former public schoolboy who had lived in Australia and Canada before returning to Britain in 1933 to become business manager for the popular Jack Hylton Band. He had given this up to establish an import business in Sweden in 1938.
The explosives were taken from the embassy by car and transferred to Rickman's 1937 Plymouth sedan in a quiet country lane in the Stockholm suburb of Danderyd.
Rickman had a Swedish girlfriend, Elsa Johnson. In keeping with his flamboyant approach, he referred to her in coded messages to the Secret Service in London as ''A1.''
In their apartment in a smart part of downtown Stockholm Rickman and Elsa stored 53.6 kilos of the explosives. In Rickman's office were another 57.3 kilos , 8 mines, and 320 magnesium fire bombs.
Ernest Biggs, an English advertising consultant who lived in Stockholm, was recruited by Rickman to help in the raid on Oxelosund. So was Arno Behrisch, a German who was eager to work against Hitler for ideological reasons.
In February 1940 two attempts by Rickman, Elsa, Biggs, and Behrisch on the cranes at Oxelosund had to be abandoned when it was found they were still in use. (London had stipulated no loss of life).
Then on April 19, 1940, when the quartet were about to try for a third time, police staged a series of raids. The four conspirators were arrested and the explosives seized.
Their trial was held in Stockholm in strict secrecy. Rickman was jailed for eight years, Biggs for five, and Elsa and Behrisch got three and a half years each.
Statements made by the accused show quite clearly that two attempts were actually made to put Operation Strike Ox into effect and that a third was planned. This is at odds with the account given in ''A Man Called Intrepid'' (Macmillan 1976), best-selling autobiography of Sir William Stephenson by William Stevenson.
According to this, Operation Strike Ox was merely a well-planned feint aimed at misdirecting German attention, ''allowing Stephenson to reinforce a network of friendly Swedes. They had a cryptologic bureau that systematically broke the codes of their neighbors.'' Strike Ox was ''pure deception,'' Stephenson says. ''The melodrama reached its intended climax.'' According to his account, it was canceled by Lord Halifax, the then British Foreign Secretary, before any attempt had been made to put it into effect.
Operation Strike Ox was just one of three plans to violate Swedish neutrality studied by the British War Cabinet, Dr. Munch-Petersen claims.
One of these, involving a commando raid on the Lappland ore fields from Norway, was actually put into initial operation with a task force sent to Narvik in northern Norway, but it was finally vetoed by the War Cabinet.
A third plan to mine or block Lulea Harbor had to be abandoned when ''some information on the scheme . . . slipped out to the Swedes.''
The trial of Rickman and his fellow conspirators reveals that they were also involved in producing propaganda aimed against Swedish neutrality.
It would seem likely that it was the production of tracts with titles such as ''Sweden Awake'' and ''Is This Neutrality?'' that first alerted the Swedish police to their activities.
Comic interludes lighten the transcript of the court case. On one reconnaissance trip to Oxelosund, Rickman's Plymouth skidded into a ditch not far from the harbor. The shamefaced conspirators had to telephone for a vehicle recovery unit from the nearby town of Nykoping to pull them back onto the road.
Then there is a statement by Elsa in which she says she complained to Rickman about the danger of having so much high explosives in their apartment. The suave Rickman assured her they were a new sort of explosive and there was no danger.