The 14th January 1943 directive advised that as a result of the increased menace of the U-Boat, approval had been obtained to bomb the U-Boat operational bases on the west coast of France, including the local facilities such as water, power and electricity that the bases were dependent on.
Targets included Lorient, St Nazaire, Brest and La Pallice
The 21st January 1943 directive (known as the Casablanca Directive) stated that Bomber Command’s primary objective continued to be “the progressive destruction of the German military, industrial and economic system and the undermining of the morale of the German people to a point where their capacity for armed resistance is fatally weakened”
The order of priority was shown as (a) German submarine construction yards (b)the German aircraft industry (c) Transportation (d) Oil Plants (e) Other targets in enemy war industry.
The 6th April 1943 directive stated that attacks against the German submarine construction yards should be discontinued.
The 10th June 1943 directive stated that the growing strength of German fighters was causing concern and as such the bomber offensive should focus on targets associated with the construction and storage of German aircraft.
The 3rd September 1943 directive stated that the objective of the bomber offensive was redefined as “The progressive destruction of the German military, industrial and economic system, the disruption of vital elements of lines of communication and the material reduction of German air combat strength”. It added that the offensive was a prerequisite to “Operation Overlord”