Officers would be instructed to try a soft approach first, in particular towards the civilians; the soldiers should behave as friends and protectors, not aggressors. Bombers and long-distance fighters would be over the cities, ports and military installations to enforce the order, but without bombing or strafing unless deemed necessary by those on the ground. Von Falkenhorst later held that he hoped a ‘peaceful occupation’ could be achieved through a non-aggressive but ‘firm, soldierly behaviour’, but feared the Norwegians would resist.24 It would have to be left to the man in charge of each group to decide which actions to take, when to bluff and when to open fire. Tasks would inevitably be solved differently, with different outcomes.
The bridgeheads in the west would have supply lines at the mercy of the Royal Navy. Hence, there would be no means of reinforcement other than by air until overland contact had been established. It would be necessary to bring sufficient troops and supplies in the initial landing phase to secure control and to initiate break-out operations towards the main force, which would move out from the Oslo region. Narvik would remain isolated until superiority in the south had been secured. On the positive side, the Allies would have few places left to land, should they attempt to intervene.25
The warships could not carry sufficient supplies to sustain the invasion forces and a carefully timed supply operation was set up whereby a handful of tankers and transport vessels would arrive at the invasion ports after the warships.26 There was grave concern in the SKL over the safety of these ships, as they would have to leave Germany several days ahead of the naval ships and travel through Norwegian waters with no protection other than camouflage. Additionally, as the ports in western Germany could not accommodate the entire invasion and support fleet, some ships would have to pass through the Danish Belts, where they would undoubtedly be observed.27
After some debate between the OKW and the army, six divisions were eventually assigned to occupy Norway: 3rd Mountain Division and 69th, 163rd, 181st, 196th and 214th Infantry Divisions (ID). None of the units had combat experience, except for the 3rd Mountain Division, which had been partly used in Poland, and officers and NCOs who had transferred from other units. The 170th and 198th ID were assigned to Denmark, together with the 11th (motorised) Rifle Brigade. All units had a lower than usual complement of artillery and motor vehicles, but this was considered acceptable for operations in Scandinavia.
Around 8,850 men would be on board the warships heading for Norway in the first attack wave, while the airborne contingent would be some 3,500 men. The transport ships would land an additional 3,900 men, 742 horses, 942 vehicles and four tanks on the invasion day. Altogether there would be less than sixteen thousand men in the first wave, roughly the size of a regular German division. Not much to seize a whole country, but reinforcements of men and matériel would follow by air and sea as fast as possible. Most of these would go to Oslo in the ships of the sea transport echelons. The route east of Denmark to the Oslofjord would be the shortest and furthest away from the Royal Navy and the RAF. Weather was also less hazardous here than in the North Sea. Within three days, eight thousand troops were to be transported by air and sea, and an additional 16,700 during the subsequent week. In all a hundred thousand men would be brought to Norway in a continuous shuttle.
The British Navy was seen as the main threat to the operation, not only at sea but also in terms of counter-attacks. The guns of the Norwegian coastal fortifications were needed for defence against such an attack, and naval gunners would be onboard the ships of the first wave to man them as soon as possible. Raeder knew there was reason to fear the guns of the coastal forts during the invasion even if there was a good chance they might not be able to open fire in time unless they were pre-warned. He believed that few Norwegian officers would open fire on British ships; in the initial operation order, signed on 6 March, the warships were instructed to fly British flags until just before disembarkation commenced. All challenges from patrol vessels or coastguard stations should be answered in English. The exception was Narvik, where the local commander, Oberst Sundlo, was known to be German-friendly and was expected to react positively to German flags. According to international conventions, the use of false flag is permitted as a ruse of war until fire is opened, when own flag shall be flying. The order nevertheless created massive protests from some of the commanders, among them Oberst Buschenhagen and Generalmajor Tittel of the 69th ID. The order was eventually recalled by radio in the afternoon of 8 March and the German ships did not use British flags when entering Norwegian ports.28
Virtually the entire Kriegsmarine would be directly involved and all other naval operations were suspended, including U-boat sorties and preparations for the offensive in the West. Not everybody appreciated this and on 28 March, General Jodl noted in his diary that ‘Some naval officers are lukewarm concerning Weserübung and need a stimulus . . . Falkenhorst’s three chiefs of staff are having thoughts that are not their business. Krancke sees more drawbacks than advantages,’ without elaborating. Von Falkenhorst commented later that Krancke ‘at times did not agree with the plans of the Führer, criticising his decisions with sharp words.’29
Once the invasion had started, the Royal Navy would be alerted, whatever the security, and the SKL wished for the warships to return as soon as possible to try to avoid interception. The army argued that they would need the guns of the warships for support in case of opposition or Allied countermeasures and demanded that the navy stayed. Hitler agreed with the army and insisted that destroyers should be left behind in Narvik and a cruiser in Trondheim. Raeder held it was more important to have the ships available at sea rather then locked up in the fjords, and promises from Göring that the Luftwaffe would secure their stay inshore were dismissed as uncertain and weather-dependent. On 29 March Raeder discussed the issue with Hitler in private. He must have had some good arguments, as the Führer accepted that all destroyers could return from Narvik. At Trondheim he was firm: some destroyers should remain. A couple of days later, the SKL obliged, concluding that ‘The Kriegsmarine has a commitment to protect the troops also after disembarkation and it may become necessary to leave some ships behind . . . until the army can no longer be hindered by Norwegian naval forces from fulfilling their task.’
After the invasion, the iron-ore traffic from Narvik would no longer be protected by Norwegian neutrality and a sustainable defence of the Norwegian coast would require a significant reorganisation of the Kriegsmarine’s resources. The larger ships would be needed elsewhere and available forces would be limited to smaller vessels and U-boats. As many of the Norwegian ships as possible would have to be captured intact and pressed into service, however obsolete. It was to be expected that transit of ore through Narvik would cease until the Norwegian sea lanes had been secured by minefields, coastal batteries and air patrols. This would take time, perhaps several months. To handle matters after the invasion, Admiral Hermann Boehm was designated ‘commanding admiral Norway’: Raeder’s direct representative, with headquarters in Oslo. Reporting to him, would be ‘admiral south coast’ in Kristiansand, Konteradmiral Otto Schenk, and ‘admiral west coast’ in Bergen, Vizeadmiral Otto von Schrader; the port commanders in Trondheim, Narvik and Stavanger reporting to the latter. These officers and their staffs were to become involved in the final stages of the planning and would be onboard the invasion vessels to take charge from day one.30
Göring and his Chief of Staff, General Jeschonneck, were annoyed over the downgrading of the Luftwaffe in Operation Weserübung, claiming they had been kept in the dark.31 Never one for co-operation or sharing of influence, Göring feared that the subordination of Luftwaffe units to an overall operational command would threaten his authority. Antiaircraft (A/A) units, airfield engineers, staff and maintenance personnel would be flown into Norway and Denmark as soon as the airfields were secured and there was no way the Luftwaffe could accept losing control over