Abbey of Monte Cassino is Pulverized by Allied Bombs
Increasingly, the opinions of certain Allied officers were fixed on the great abbey of Monte Cassino: in their view it was the abbey—and its presumed use as a German artillery observation point—that prevented the breach of the ‘Gustav Line'.
The British press and C. L. Sulzberger of The New York Times frequently and convincingly and in (often manufactured) detail wrote of German observation posts and artillery positions inside the abbey. The commander in chief of the Mediterranean Allied Air Forces Lieutenant-General Ira C. Eaker accompanied by Lieutenant-General Jacob L. Devers (deputy to General Sir Henry Maitland Wilson, the Supreme Allied Commander of the Mediterranean Theater) personally observed during a fly-over “a radio mast [...] German uniforms hanging on a clothesline in the abbey courtyard; [and] machine gun emplacements 50 yards (46 m) from the abbey walls.” [nb 1] Major-General Geoffrey Keyes of U.S. II Corps also flew over the monastery several times; he then reported to Fifth Army G-2 that he had seen no evidence the Germans were in the abbey. When informed of others who had claimed to have seen Germans in the abbey, he stated: “They’ve been looking so long they’re seeing things."
The view in New Zealand Corps HQ, as articulated in the writings of Major-General Kippenberger, was that the monastery was probably being used as the German's main vantage point for artillery spotting, since it was so perfectly situated for the purpose that no army could refrain from using it. There is no clear evidence to this effect, but he went on to write that from a military point of view the current state of occupancy of the monastery was immaterial:
"If not occupied today, it might be tomorrow and it did not appear it would be difficult for the enemy to bring reserves into it during an attack or for troops to take shelter there if driven from positions outside. It was impossible to ask troops to storm a hill surmounted by an intact building such as this, capable of sheltering several hundred infantry in perfect security from shellfire and ready at the critical moment to emerge and counter-attack. ... Undamaged it was a perfect shelter but with its narrow windows and level profiles an unsatisfactory fighting position. Smashed by bombing it was a jagged heap of broken masonry and debris open to effective fire from guns, mortars and strafing planes as well as being a death trap if bombed again. On the whole I thought it would be more useful to the Germans if we left it unbombed".
Major-General Francis Tuker, whose 4th Indian Division would have the task of attacking Monastery Hill, had made his own appreciation of the situation. In the absence of detailed intelligence at U.S. 5th Army HQ, he had found a book dated 1879 in a Naples bookshop giving details of the construction of the abbey. In his memorandum to Freyberg he concluded that regardless of whether the monastery was currently occupied by the Germans, it should be demolished to prevent its effective occupation. He also pointed out that with 150 foot (45 m) high walls made of masonry at least 10 feet (3 m) thick, there was no practical means for field engineers to deal with the place, and that bombing with "blockbuster" bombs would be the only solution since 1,000 pound bombs would be "next to useless".
On February 11, 1944, the acting commander of 4th Indian Division, Brigadier Harry Dimoline, requested the bombing of the abbey of Monte Cassino. Tuker reiterated again his case for bombing the monastery from his hospital bed in Caserta, where he was suffering a severe attack of a recurrent tropical fever. Freyberg transmitted his request on February 12. Freyberg's request for an air attack, however, was greatly expanded by air force planners, and probably supported by Ira Eaker and Jacob L. Devers. They sought to use the opportunity to showcase the abilities of U.S. Army air power to support ground operations. Lieutenant-General Mark W. Clark of Fifth Army and his chief of staff Major-General Alfred Gruenther remained unconvinced of the “military necessity”. When handing over the U.S. II Corps position to the New Zealand Corps, Brigadier General J.A. Butler, deputy commander of U.S. 34th Division, had said "I don't know, but I don't believe the enemy is in the convent. All the fire has been from the slopes of the hill below the wall". Finally Clark, "who did not want the monastery bombed," pinned down the Commander-in-Chief Allied Armies in Italy, General Sir Harold Alexander to take the responsibility: "I said, 'You give me a direct order and we’ll do it,' and he did."
The bombing mission in the morning of February 15, 1944 involved 142 B-17 Flying Fortresses together with 47 B-25 Mitchell and 40 B-26 Marauder medium bombers. In all they dropped 1,150 tons of high explosives and incendiary bombs on the abbey, reducing the entire top of Monte Cassino to a smoking mass of rubble. Between bomb runs, the II Corps artillery pounded the mountain. Many Allied soldiers and war correspondents cheered as they observed the spectacle. Eaker and Devers watched; Juin was heard to remark “... no, they’ll never get anywhere this way.” Clark and Gruenther refused to be on the scene and stayed at their headquarters. That same afternoon and the next day, in an aggressive follow-up, further artillery barrages and additional tonnage onto the ruins by 59 fighter bombers convulsed the rubble of the great abbey.
The air raid however, had not been coordinated between the air and ground commands, with the timing driven by the Air Force projecting it as a separate operation, considering the weather and to be fitted in with other requirements on other fronts and theaters and without reference to the ground forces (indeed, the Indian troops on the Snake's Head were taken by surprise when the bombing actually started). The raid took place two days before the New Zealand Corps was ready to launch their main assault. Many of the troops had only taken over their positions from U.S. II Corps on February 13, and besides the difficulties in the mountains, preparations in the valley had also been held up by difficulties in supplying the newly installed troops with sufficient material for a full-scale assault because of incessantly foul weather, flooding, and waterlogged ground.
After the bombing
Directly after the bombing, German troops included the ruins of the Abbey into their defence positions, which remained impregnable for the aggressors also in the next months. Only a withdrawal for the armed forces in a northward direction, which was commanded by Kesselring on the 17th May due to the precarious military situation in Italy, enabled Polish exile associations to take over the Abbey a day later.