At Sullom Voe, the C-in-C of 2nd Destroyer Flotilla, Captain (D)2 Bernard Warburton-Lee wrote in a letter to his wife Elisabeth dated 4 April, after learning that he was to escort the minelayers to Vestfjorden: ‘. . . the war is going to start quite soon – I am going to start it.’97 Not even he could imagine that German naval units were already preparing to take to sea.
Rubicon
During March, intelligence mounted in Berlin, indicating consistent Allied pressure on the Norwegian government to allow transit of troops to Finland and the establishment of bases in Norway. There would be protests, said the reports, but only nominal and no opposition would be offered. One report for instance, arriving via Scheidt, held that ‘a person close to both the King and Commanding Admiral’ considered a British intervention ‘unavoidable’ – and it would come ‘very soon’. Another agent reported with certainty that ‘England had requested right of passage through Narvik and a naval base in Kristiansand.’ Further reports alleged that Allied officers were surveying Norwegian ports with tacit Norwegian acceptance. In an unsigned report to SKL dated 5 March, it is stated that the Norwegian government had given in to French and British pressure and accepted ‘transit of Allied troops and the establishment of points of support’ on the Norwegian coast. It was part of the alleged agreement that the Norwegian government should deny the existence of any accord and should protest verbally against the Allied intrusions, as it had done during the Altmark episode.98 Further reports of increased British air reconnaissance, agent activity in Norway, troopship concentrations in Scotland, French Alpine troops embarking ships in the Channel ports, the return of the British Home Fleet to Scapa Flow and heavy cruisers withdrawn from the Northern Patrol, augmented the picture: large-scale Allied landings in Norway were under development.
There was little doubt in Berlin that, in spite of the expressed grief over Finland, the real objective of the Allied landings was to sever the iron-ore traffic to Germany and capture bases in Norway. Hitler decided Germany would have to act ‘quickly and decisively’.
‘Full speed ahead for Weserübung,’ Halder noted in his diary on 4 March and the next day Hitler for the first time discussed Weserübung with all three service commanders present. Two days later, he declared that the occupation of Norway and France should be planned independently and that the disposition of forces, as suggested by von Falkenhorst, was final and no longer subject to change. To avoid any provocation, it would be necessary to inform the Russians prior to the attack and let them know that the occupation of northern Norway was only for the duration of the war with Britain.99
‘Operations Order No. 1 for the Occupation of Norway’ was issued by von Falkenhorst on 5 March. Weserübung was ready to be launched, but the persistent severe ice conditions in the Baltic meant a number of the warships and transports were confined to port and there was growing concern that the Allied intervention in Scandinavia could be initiated any day. On the 6th, General Halder noted in his diary that it had been ascertained that the Allies had requested free transit of troops for Finland through Sweden and Norway, adding ‘the Führer will now act.’100
In a status meeting with Hitler and von Falkenhorst on 9 March, Admiral Raeder held that in his opinion the current development of the situation in Finland made Weserübung ‘urgently necessary’. If the Allies were to use the pretext of helping Finland, as intelligence indicated, they would certainly occupy Norway and Sweden en route, completely severing the supply of iron ore and establishing offensive bases. Raeder added that it was his duty to point out that Weserübung contradicted all principles of naval warfare, as it would have to be carried out in the face of a superior British fleet. He was convinced, though, that the operation would succeed, if complete surprise could be obtained.
On 10 March, it was noted in the SKL War Diary that ‘. . . the totality of the reports point in a compelling manner towards the possibility of immediate action by the Allies in Norway.’ Radio intercepts during the 13th tracked no less than thirteen British submarines deployed in the North Sea and at the entrance to the Skagerrak, with two more underway from Rosyth. This was more than twice the usual number and a clear signal that something was going on. Most likely, the boats were covering the flank of an Allied landing operation in Norway that appeared from other intelligence to be developing. Nothing was ready on the German side and as news was coming in from Moscow that Finland had capitulated, it was decided to do nothing, other then alerting U-boats in the area to be extra vigilant.101
On the 15th, further intercepted signals ordering the submarines to disperse revealed that the Soviet–Finnish ceasefire had indeed upset the Allied plans. Interpretation of the signals indicated the operation was not cancelled, just put on hold with forty-eight to ninety-six hours’ notice. Oberst Warlimont concluded in a memorandum to Jodl that he believed the pretext for an Allied intervention in Norway had gone and that Operation Weserübung should be cancelled and the forces released. The SKL took a more conditional stance:
The consequence of the Finnish–Russian ceasefire for Germany’s warfare is as yet unclear. The Allied plans for an immediate landing in Norway . . . seem to have been deferred for the moment. The SKL believes England’s strategic goals in the north have not changed and the planned action will be initiated when another favourable occasion has been found.102
At the Führer conference on 26 March, intelligence was presented showing how close an Allied intervention in Norway had been when the Finnish–Russian ceasefire was announced. Raeder added that even if the imminent danger of such an operation had been reduced, the ultimate objective of the Allies to sever the iron-ore supplies to Germany remained and an intensified effort against German merchant traffic in neutral waters was to be expected. Sooner or later, Allied plans for an intervention in Norway would re-emerge and Germany would have to carry out Weserübung. The operation had originated from the premise that Germany could not accept British control of Norwegian territory and that only a pre-emptive occupation could avert that. Therefore, Raeder suggested, Weserübung should be initiated in the next new-moon period and no later than 15 April. Everything was ready and the dark nights needed to cover the transit would soon become too short, increasing the overall risk to the operation. Virtually all operational U-boats had been deployed along the Norwegian coast or in the North Sea during March and would start running low on fuel and provisions in mid-April, thus closing the current window of opportunity. Sooner or later it would also be noted in London that other naval operations had been suspended. Earlier in the day, Raeder said, he had met with Hagelin and learned that the Norwegian Admiral Staff expected British naval forces to take control of the Norwegian Leads soon in a ‘staged provocation’, followed by seizure of naval and air bases in southern Norway. Hagelin believed that the Norwegian government would, at the most, offer only symbolic opposition. Careful as always, Raeder added that in spite of intelligence reports to the contrary, he personally was not sure an Allied intervention in Norway was imminent.103 Hitler concluded that it was not to be expected that the Allies had abandoned their strategy in the north; threats of a German attack in France could trigger an Allied intervention in Norway. Hence, a preliminary date for Weserübung was set for between 8 and 10 April. The SKL, on Raeder’s instruction, issued orders that all ships should remain on stand-by and arrangements for embarkation of troops and equipment continued until further notice – as should all security measures.104
In the evening of 26 March, Kapitänleutnant Wolf-Harro Stiebler lost his bearings during a snowstorm in the Skagerrak and ran his boat U21 firmly onto Oddskjæret, one of the southernmost rocks of the Norwegian coast, well inside territorial waters. The Norwegian government wished to make a stand and decided to intern the boat and its crew. A minor diplomatic crisis ensued, but Germany could not afford a disturbance at that moment and Kapitänleutnant Stiebler and U21 were sacrificed for the greater cause. He was ordered to escape if possible and that was it.105
The news from the Supreme War Council meeting on 28 March was taken as evidence that it had been correct to assume that
