In January 1945 the British air ministry drew up plan THUNDERCLAP for attacks on Berlin and population centres in eastern Germany. This was to take advantage of the recently launched Soviet offensive westwards from the Vistula and add to the growing chaos in Germany by disrupting the flow of refugees fleeing in the face of the Soviet attack.

At the same time, the western Allies wished to demonstrate to the Soviets at the forthcoming Yalta conference that they were giving them the support of their heavy bombers, and, indeed, at Yalta the Soviets specifically requested help in this form.

In the meantime, Spaatz and Harris, commanding the US and British bombing forces, had received orders for THUNDERCLAP to be put into action, and the first operations of it were US daylight attacks on Berlin and Magdeburg on 3 February, Chemnitz and Magdeburg akin on the 6th, and Magdeburg yet again on 9 February.

Air Chief Marshal Harris's intention had been to strike Dresden first, but weather conditions were initially unfavourable. On 13 February they showed improvement, although not good enough for the original plan of an initial US attack during the day. That night, however, RAF Bomber Command despatched 796 Lancaster bombers and 9 Mosquitoes from the UK. These attacked Dresden in two waves three hours apart, dropping 1,478 tons of high explosive bombs and 1,182 tons of incendiaries which started a firestorm.

Such was the weakness of the air defences that only six Lancasters were shot down, although a further three crashed on friendly territory on the way home. The following day, 311 US B17 bombers also struck the city, adding to the extensive damage caused by the RAF. In all, some 50,000 people, including many refugees, are reckoned to have lost their lives and much of the city was devastated.

At a SHAEF press briefing two days later it was revealed in 'off the record' comments that the aims of THUNDERCLAP were to bomb large population centres and prevent relief supplies from getting through. An Associated Press war correspondent immediately filed a story that the Allies had resorted to terror bombing in order to seal Hitler's doom and this set in train a number of embarrassing questions on both sides of the Atlantic on the morality of this form of attack.

Eventually, even Churchill, who had been a wholehearted supporter of THUNDERCLAP, went so far as to comment to the British Chiefs of Staff that 'the destruction of Dresden remains a serious query against the conduct of Allied bombing.'

Harris, however, remained unrepentant, commenting on Churchill's objection that he did not regard 'the whole of the remaining cities of Germany as worth the bones of one British Grenadier'. Even so, Dresden remains the prime example cited by those who condemn the morality of 'city busting'.