An historical postscript can now be added to the much discussed question of the destruction of the historic Benedictine Monastery on Monte Cassino as a preliminary step in the Allied offensive there in February. The task was carried out by a large force of American bombers and supporting artillery. According to the announcements of the Allied Command at the time this destruction was ordered because the Monastery, which dominated the approaches to the town, had been "occupied and fortified" by the Germans. These statements were repeated in Field-Marshal Sir H. Maitland Wilson's report published in 1946 - which seemed strange in view of earlier testimony from the Vatican and the Abbot himself that the Germans had avoided trespassing on the Monastery, despite the tactical disadvantage which this involved for them.

The irony of the bombing was, as both Senger and Vietinghoff remarked, that it turned out entirely to the tactical benefit of the Germans. For after that they felt free to occupy the ruins, and the rubble provided mud better defensive cover than the Monastery would have been before its destruction. As anyone with experience of street-fighting knows, it is only when buildings are demolished that they are converted from mouse-traps into bastions of defence. Batteries posted and concealed in the ruins were able to enfilade and break up the subsequent British attempts to drive through to the town of Cassino.

The battle for Cassino-or rather the series of battles for Cassino - began on 17 January 1944, when X Corps attacked across the Garigliano. On 20 January, United States II Corps attacked across the Rapido, but this blow failed and X Corps, after meeting with some initial success, were checked by heavy counter-attacks. One more attack began on 16 February, and it was this assault that was preceded by the destruction of the monastery by bombing and artillery fire. But Cassino town and the monastery were not to be captured until 18 May, when the Poles raised the red and white standard with the white eagle over the ruins of the monastery.

Till the February bombardment, the great Benedictine monastery had been spared deliberately, to our detriment. Whether the Germans took advantage of its deep cellars for shelter and its high windows for observation I do not know; but it was obvious that this huge and massive building offered the defenders considerable protection from hostile fire, merely by their sheltering under its walls. As Winston Churchill has observed, the enemy fortifications were hardly separate from the building itself.

Was the destruction of the monastery a military necessity? Was it morally wrong to destroy it?

The answer to the first question is 'yes'. It was necessary more for the effect it would have on the morale of the attackers than for purely material reasons.

The answer to the second question is this: when soldiers are fighting for a just cause and are prepared to suffer death and mutilation in the process, bricks and mortar, no matter how venerable, cannot be allowed to weigh against human lives. Every good commander must consider the morale and feelings of his fighting men, and, what is equally important, the fighting men must know that their whole existence is in the hands of a man in whom they have complete confidence. Thus the commanding general must make it absolutely clear to his troops that they go into action under the most favourable conditions he has the power to order.

In the context of the Cassino battle, how could a structure which dominated the fighting field be allowed to stand? The monastery had to be destroyed. Withal, everything was done to save the lives of the monks and their treasures: ample warning was given of the bombing.

The great Benedictine monastery, from which a magnificent view of the surrounding country can be gained, has been completely rebuilt in cut stone. Both outside and in, it has been restored to its former condition, even down to the marble work and interior decoration.

The bombs of the Allied air forces had left nothing of the building standing except part of one of the outer walls - all else was a heap of rubble. Yet amidst this appalling destruction St. Benedict's tomb, in the centre of the monastery, went utterly unscathed.

After the capture and liberation of Rome I was able to tell the late Pope of its survival. He was deeply moved. He assured me, moreover, that he well understood the military necessity for the bombing and the inevitable destruction of the monastery.

Field-Marshal Kesselring had given express orders that no German soldier should enter the Monastery, so as to avoid giving the Allies any pretext for bombing or shelling it. I cannot testify personally that this decision was communicated to the Allies but I am sure that the Vatican found means to do so, since it was so directly interested in the fate of Monte Cassino. Not only did Field-Marshal Kesselring prohibit German soldiers from entering the Monastery, but be also placed a guard at the entrance gate to ensure that his orders were carried out.

Another lesson which I think has been, not learned perhaps, but confirmed in recent fighting in Italy is that the immediate battlefield is not the place to use the bomber, even the fighter-bomber. I have made many bad shots in the past, but one thing I have always said (and have in the past year or two often been twitted for having said) is that the bomber is not a battlefield weapon.

Here is a scene of utter desolation such as only this war can produce. It is nearing noon and the last Germans left this relic of a tortured town some few hours ago. They were prisoners. Their last stronghold - the Continental Hotel - had gone up with a bang a little while before that. It was the final retreating blow that the Germans in Cassino struck.

There were fewer than thirty prisoners taken in Cassino itself. Our men felt bitter about that. "This is the first time I have ever been able to stand outside in the open air," said one of them, "and now I have only seen ten Germans."

He had come into the open air to stand bolt upright for the first time this morning. He had come from a dug-out that was in the rubble of a battered house where day was dark as night, and where only in the hours of darkness you dared to crawl out so that the next section to hold this post might crawl in.

A little behind us is "The Crypt." Its rightful ecclesiastical name - for it is below the chapel of a convent - remained relevant in the cruel circumstances of war. It had had ninety-nine direct hits on it from German shells up to the arrival of the British troops who took over about ten days ago. Since then it has received fifteen direct hits.

They tell one that nothing less than a direct hit from a 1,000lb bomb would penetrate the crypt. That is some measure of the protection which the Germans enjoyed last March when the Allied Air Forces bombed this town in the greatest strength ever put on a target of comparable size.

The crypt inside and outside might pass for any front-line soldier's picture of a dig-out. Its dangers were supremely the dangers of the front line itself. One British sergeant whose head was visible in daylight above its entrance for less than a split second was killed. Enemy snipers never left this spot uncovered. So it was all through Cassino - ceaseless, vigilant watching, with every opportunity seized by both sides to strike down whoever could be seen to move.

Much of this town is built flush with the rock of the hillside up which winds the road to the monastery on Monte Cassino. so much is this the case that to-day, in its bare remnants of shattered walls, Cassino looks just as if it were mainly a series of caves in the hillside.

Castle Hill, rising sheer within the town on its north side, stands like a steep crag, its pinnacle a jagged rock now unrecognisable as buildings. The castle itself had remained in our hands since the latter part of March. Below it the ruins of houses were in the hands of the Germans. Thus our own troops on the top of Castle Hill were just above the Germans, who in turn were only about fifty yards from another line of our troops in the opposite direction, towards the centre of the town and the River Rapido. This was a typical example of how our own positions and the enemy's in the town were close upon each other in a series of loosely formed lines, almost intermingling.