before the war, but Operation Eagle Attack and the following Battle of Britain had got in the way of striking at Britain's sea communications and diverted German air strength to the campaign against the RAF and its supporting structures. The OKL had always regarded the interdiction of sea communications of less importance than bombing land-based aircraft industries. Directive 23 was the only concession made by Göring to the Kriegsmarine over the strategic bombing strategy of the Luftwaffe against Britain. Thereafter, he would refuse to make available any air units to destroy British dockyards, ports, port facilities, or shipping in dock or at sea, lest Kriegsmarine gain control of more Luftwaffe units. Raeder's successor—Karl Dönitz—would—on the intervention of Hitler—gain control of one unit (KG 40), but Göring would soon regain it. Göring's lack of co-operation was detrimental to the one air strategy with potentially decisive strategic effect on Britain. Instead, he wasted aircraft of Fliegerführer Atlantik (Flying Command Atlantic) on bombing mainland Britain instead of attacks against convoys. For Göring, his prestige had been damaged by the defeat in the Battle of Britain, and he wanted to regain it by subduing Britain by air power alone. He was always reluctant to co-operate with Raeder. Even so, the decision by the OKL to support the strategy in Directive 23 was instigated by two considerations, both of which had little to do with wanting to destroy Britain's sea communications in conjunction with the Kriegsmarine. First, the difficulty in estimating the impact of bombing upon war production was becoming apparent, and second, the conclusion British morale was unlikely to break led the OKL to adopt the naval option. The indifference displayed by the OKL to Directive 23 was perhaps best demonstrated in operational directives which diluted its effect. They emphasised the core strategic interest was attacking ports but they insisted in maintaining pressure or diverting strength, onto industries building aircraft, anti-aircraft guns, and explosives. Other targets would be considered if the primary ones could not be attacked because of weather conditions. A further line in the directive stressed the need to inflict the heaviest losses possible, but also to intensify the air war in order to create the impression an amphibious assault on Britain was planned for 1941. However, meteorological conditions over Britain were not favourable for flying and prevented an escalation in air operations. Airfields became water-logged and the 18 Kampfgruppen (bomber groups)