I think this extract from John Terraine's The Right of The Line is appropriate

"As to the morality of the methods adopted in the bomber campaign it will be apparent to this author among others area bombing provides a most displeasing spectacle but equally clear to me is the force of what Dr Noble Frankland told his audience at the RUSI in December 13 1961 -

The great immorality open to us in 1940 and 1941 was to lose the war against Hitler's Germany. To have abandoned the only means of direct attack which we had at our disposal would have been a step in that direction."