the Germans to build German U-boat strength to one-third the displacement tonnage of the entire Royal Navy. In fact, the Germans had been developing submarines as early as 1922, despite the Treaty of Versailles and the banning of German military submarines. In the RAF, which in April 1918 was created by merging the RNAS and RFC, there still existed a place for maritime aviation. However the Navy expected the RAF to hand back the naval component after the war, which was reasonable considering the indifference the RAF displayed towards the submarine campaign in the 1914–1918 conflict. The failure of the RAF to do so started a power struggle between the Air Ministry on one side and the Admiralty and War Office on the other. The Air Ministry found its existence threatened and resolved to fend off the attempts of the Admiralty and War Office to break up the RAF and recover the RFC and RNAS by offering a cheaper, innovative alternative strategy for British air power in the future. The RAF, under the direction of a new Chief of the Air Staff (CAS) Hugh Trenchard, adopted the strategic bombing theory of air power theorists such as Giulio Douhet, who argued that air power could win wars on its own, bypassing the need for armies and navies. Maritime aviation and the valuable lessons of the First European war were cast aside, but crucially the appointment of Trenchard and his views, the removal of the weaker personalities such as CAS Frederick Sykes, and the continued support of Winston Churchill saved the Air Ministry from being disbanded. In July 1923, Trenchard sent a memorandum to AOC (Air Officer Commanding) Central and AOC Coastal Areas advising them the strategic area offensive would be the dominating policy of future conflicts, and the Coastal services would take part in such operations. In doing so Trenchard stated openly that the goals of the Air Arm in no way conflicted with either the Army or Navy. This meant that maritime, or "auxiliary" squadrons would be radically reduced to allow the focus on land-based bombers and fighters for air attack and defence in line with the RAF's "non-specialisation policy". In the 1920s, Bomber and Fighter forces were expanded while Coastal Area was continually downgraded. By 1920 little remained of Coastal Area Air Forces. With Trenchard's policy unequivocal, for both military and political reasons, maritime aviation was in danger of