[5] At the January 1943 Casablanca Conference, the Combined Chiefs of Staff agreed to conduct the Combined Bomber Offensive (CBO), and the British Air Ministry issued the Casablanca directive on 4 February with the object of:[6] The progressive destruction and dislocation of the German military, industrial and economic systems and the undermining of the morale of the German people to a point where their capacity for armed resistance is fatally weakened.

[citation needed] Long-range fighter operations are at a natural disadvantage; friendly ground assets like spotters and radar are not available and even radio support can be difficult.

[citation needed]Arnold's letter said that he felt the fighters should have been fitted with additional fuel tanks and bombs and used against the German aircraft on the ground at their airfields.

Portal responded saying that the day-force strength averaged 1,464 fighters and that it had "consistently been employed offensively... mainly in conjunction with medium and light bombers".

Two Mark IXs were shipped to Wright Field in January 1944 and modified, demonstrating their newfound range by flying back to England across the Atlantic.

Tests at Boscombe Down were equally successful, but by the time the conversions had been approved in August, Pointblank had concluded and the Luftwaffe had been conclusively defeated.