Ottmer writes that the German Abwehr, and therefore presumably the Chancery, knew the facts of the betrayal. They did not know, however, how the enemy would react to this information. Ottmer also writes that it seems this “factor of uncertainty” was not made known to Group XXI.6 If the German authorities knew about this breach of security, they obviously did not know who had made the disclosure.
Warnings Received by the Norwegians
Intelligence about suspicious activities in northern Germany reached the Scandinavian countries at least a week before the date set for the attack. Reports from Sweden, Denmark, and Germany about unusual activities began to flow into offices in Oslo during the last week of March 1940. These included rumors that the Germans were preparing to cross the Danish border and that military leaves had been cancelled. The Swedish Naval Staff believed these reports indicated that the Germans were preparing to seize Norwegian harbors and airfields.
Ambassador Scheel had already sent a warning message to the Norwegian Foreign Office on April 1 where he reported the embarkation of German troops in Stettin. Scheel’s conclusion was that these troops were probably part of operations against Sweden or other areas of the Baltic and that he saw no connection between these activities and possible German operations against Norway. The Norwegian Foreign Office did not forward this report to the Norwegian military authorities.
The Swedes were concerned about what was going on in Germany’s Baltic and North Sea ports. Swedish intelligence officers, who believed that the assembly of German troops and ships in Stettin pointed to an overseas expedition, informed the intelligence division of the Norwegian Naval Staff. The Swedish Ambassador in Berlin asked the German Foreign Office for an explanation on April 2. The Swedish Naval Attaché in Berlin also forwarded a report that day stating that he had been informed that the Germans were preparing an operation against Norway in order to preempt British landings in that country. While the source for this report is unknown, the wording is similar to Ambassador Scheel’s message on April 5. However, if the date of the report is correct, neither Scheel nor the Danish Naval Attaché could be the source since they did not receive their information until the following day.
A Norwegian newspaper reporter for Aftenposten in Berlin, Theo Findahl, notified his editorial office in Oslo on April 5 that there were rumors of large troop concentrations in northern Germany. He called the same editorial office on April 7 with the news that there were plans to land 1,500,000 troops on Norway’s southern coast. The newspaper called the Norwegian Naval Staff and informed the duty officer, Captain Håkon Willoch. Admiral Diesen instructed Captain Willoch to call the Foreign Office and ask them not to print Findahl’s report. Admiral Diesen assumed full responsibility for this action before the Investigative Commission in 1946.7
The Norwegian Naval Staff received an even more ominous report during the evening of April 7 from the Norwegian Embassy in Berlin via the Norwegian Foreign Office that appeared to substantiate the earlier reports from the Swedes:
Information from a reliable source that the troop transports mentioned in my 611 message [April 1 message], 15 to 20 ships with a combined tonnage of 150,000, departed Stettin on a westerly course on the night of April 4–5. We are informed that the destination is to be reached on April 11, destination unknown.
Despite these alarming and accurate reports, neither Admiral Diesen nor his staff believed there was any danger of a German attack. The reports were discussed but the conclusion was that they dealt with German landings in the Netherlands in conjunction with an overland attack. Sir Llewellyn Woodward writes that Diesen concluded that the concentration of German troops and shipping in northern Germany was connected to the Allied plans to help the Finns.8 The Finnish-Soviet conflict had ended almost a month earlier and there is no support for Woodward’s claim in Norwegian sources. Of all reports forwarded to the navy by the Norwegian Foreign Office, only the last (Scheel’s report on April 7) was forwarded to the naval district commanders and its dispatch was delayed until the afternoon of April 8, almost a full day after receipt by the naval staff.
Some in the Norwegian Army took a more serious view of the situation and Colonel Rasmus Hatledal, the Chief of the General Staff, called for partial mobilization on April 5. The government turned down this suggestion. Hatledal was an energetic officer who was not afraid to take initiative and responsibility. This was in sharp contrast to his superior, General Kristian Laake, the Commander-in-Chief of the Army.
The warships comprising TF 5 (destination Oslo) sailed through the Great Belt, the main strait between the Danish islands, in clear weather and full daylight on April 8. The progress of the group was followed closely by Danish observation posts and reported to the Danish Naval Ministry. These reports were passed on to the intelligence section of the Norwegian Naval Staff throughout the day.
However, the first report about major German naval movements on April 8 came from the Swedish Defense Staff at 1000 hours. The report read “German naval forces consisting of the battleship Gneisenau, the heavy cruiser Blücher and the light cruiser Emden have, accompanied by numerous smaller vessels, passed through the Great Belt during the morning on a northerly course. Destination unknown.”
The Norwegians called their contact at the Danish Naval Ministry for confirmation and further information. They received a quick reply at 1043 hours:
Forty-six German räumboote [small minesweepers] and 38 armed trawlers have, according to a report from Østre Flakk Lightship, spread out in northern Kattegat but have not yet passed Skagen [the northernmost point on the Jutland Peninsula]. Gneisenau, Leipzig and Emden passed Langeland between 0600 and 0700 hours on a northerly course, followed by three torpedo boats and six armed trawlers.
Both the German and British Naval Attachés visited the Norwegian Naval Staff in the course of the morning of April
