Combined Bomber (CBO)

At the Casablanca conference in January 1943 it was decided to support Maj.-General Eaker's plan to launch a combined bombing offensive against Germany, with the British bombing at night and the Americans by day.

Portal was given the task of co-ordinating it and on 21 January the Combined Chiefs of Staff (CCS) issued the Casablanca Directive. This stated that the objective of the CBO was 'the progressive destruction and dislocation 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.'

Despite being planned in four phases between April 1943 and April 1944 the CBO only really started when the POINTBLANK Directive, which amended the Casablanca Directive, was issued by the CCS in June 1943. While listing various categories of targets, it gave absolute priority to the destruction of German fighters, and the factories where they were built, as the Normandy landings (Overlord) could not be launched until air supremacy was achieved. The Quebec conference of August 1943 upheld this high priority while abandoning attacks on German morale as a means of achieving that purpose.

POINTBLANK resulted in air offensives against Berlin, Hamburg, and the Ruhr, and raids on Schweinfurt and elsewhere, but the heavy losses sustained, and doubts about their efficacy, helped create a crisis of confidence in the CBO. Raids deep into Germany were stopped by the Americans until long-range fighters became available and good weather ensured that any losses sustained would be justified by the results, conditions which were not fulfilled until February 1944. Following the six-day operations mounted then-called Big Week - the Luftwaffe ceased to defend its air space automatically and was incapable of mounting an effective counter-attack during OVERLORD that June.

German fighter production increased throughout the CBO, and continued to do so until September 1944. What gained the Allies air supremacy over Normandy was the inability of the Germans to train sufficient fighter pilots because of a shortage of fuel, and the inferior performance of those who were trained which enabled US long-range fighters to cause heavy losses amongst them. It remains a matter of conjecture whether the CBO would have achieved more if, as was done later, it had attacked the German synthetic oil industry.