The plans and studies of peacetime had been based upon the supposition of a duel between Italy and Austria-Hungary, and the outlook changed in view of the general conflagration. The prospect of a break with Austria-Hungary was at once considered by the Italian general staff, and by Aug. 21 1914 a scheme of offensive operations had been outlined. This plan was based upon the supposition of Italy's entry into the war within a month and upon the consent of the Italian Government to provide at once for the requirements put forward by Gen. Cadorna, chief of the general staff. As neither condition was fulfilled, the plan need not be discussed, and it was in fact with- drawn by Cadorna a month later. The preparations of the winter and spring and the march of events on the French and Russian fronts determined the plan of operations which it was hoped to carry out upon Italy's entry into the war.
Gen. Cadorna, who took command of the Italian armies on the declaration of war, had worked out his scheme on the idea that Italy's object should be to hold on the N. and push towards the E. He had not sufficient strength to attack in both sectors. This decision, however, did not imply a passive defensive on the mountain front. On the contrary, the choice of the eastern sector for the main offensive demanded an active defensive, or rather a limited offensive, on the mountain front, and especially in the Trentino. If the operations towards the E. were to be developed with reasonable security it was absolutely essential to improve the position in the Trentino, to reduce, at least, the threat to Italian communications caused by the great salient. The long frontier may be divided into three sectors: (i) the Trentino salient; (2) the great barrier of the Cadore and Carnic Alps; (3) the eastern frontier from Pontebba to the sea. In the first of these sectors the Austrians had an overwhelming advan- tage in the natural lie of the terrain and the use which had been made of it. The salient was well protected on the flanks; on the W. by the great Alpine mass that is broken only by two feasible passes, the Stelvio and the Tonale, and on the E. by the mountains N. of Asiago and the great rocks of the western Dolomites, a wall that had only two gaps, the narrow valley of the Brenta and the road that runs from Feltre by Fiera di Primiero and the Passo di Rolle. The Austrians were in this position, that they could defend the salient with a comparatively small number of troops thanks to the immense natural strength of the positions they occupied and the system of fortifications which had been prepared, while within their mountain walls and behind these fortifications they could concentrate forces for an attack through the comparatively narrow mountainous zone which lay between the frontier and the plains. Three classic military routes led into Italy, through the Guidicaria, Lagarina and Sugana valleys, and other roads had opened up the difficult country between the Adige and the Brenta. East of the Trentino, from the Marmolada through the Alps of Cadore and Carnia as far as Pontebba, operations on an important scale were almost equally difficult for both sides, in face of the natural advantages that lay with the defensive. The Italians had a greater depth of mountainous zone to back their first lines, but the Austrians, with the Pusterthal and the Gailthal, were very much better off for lateral communications. The third sector of the front, from Pontebba to the sea, was less unfavourable to an Italian attack, but here also the conditions were very difficult. Between Pontebba and the Isonzo great mountains blocked the way, while the upper and middle reaches of the Isonzo flow through a wild, mountainous country with few roads. South of Tolmino indeed the mountain masses decrease in height and steepness, but the country still has the aspect of a giant ridge and furrow. The plain of Friuli narrows rapidly as it approaches its eastern limits, and at the old frontier the gap between the lagoons and the foothills of the Julian Alps is not 15 m. in width. And this gap has little depth; less than 10 m. to the E. of the old frontier begins the plateau of the Carso. The approaches from the W. are completely commanded from the Carso and the hills about Gorizia, and to the E. the ground rises again. Here, too, Italy had to fight over country where the enemy had a very great advantage in position. Still, the natural obstacles were much
less formidable towards the Isonzo than elsewhere along the frontier; communications were fair in the plain and' there was space for an attack upon a relatively wide front. Above all, a successful advance in this direction would lead somewhere, would threaten a vital part of the monarchy. An invasion of the Trentino held no such promise. At the most, success would have meant the reduction of the salient and the occupation of the " unredeemed " territories, for northern Tirol must be considered impregnable. The choice of Cadore and Carnia for the main offensive was open to the same objection. Given the strong defensive positions near the frontier, the Austrian superiority in communications and the distance of any objective of first- class importance, the prospects of an advance in strength afforded by this region were not tempting, the less so as the district afforded little in the way of supplies. There was a further argument in favour of attacking towards the E., that an attack in this direction would be calculated to occupy a much greate number of enemy troops than an attempt to advance in the mountains. The fact that Austria-Hungary was already heavily engaged elsewhere gave the Italian general staff the chan of attacking but there were corresponding obligations. The Italian campaign had obviously to be planned as part of a whole, and it was the duty of the Italian command not merely to strike for Italian aims but to cooperate in the general struggle.
Cadorna decided on the plan that offered the chance of tn greater success, and he framed his scheme of operations on th supposition that in May 1915 he could expect simultaneou offensive action on the part of Russia and Serbia. The objection to an offensive in the direction of Trieste and Laibach we obvious enough: a successful advance meant the lengthening < a front that was already very long in proportion to the numt of troops and guns available, and, moreover, increased tt menace of the Trentino salient. But the drawback was lesser by the expectation of Allied action on the N.E. and S. fronts i Austria-Hungary, which would prevent the enemy from takir advantage of this weakness.
Cadorna's plan, completed in detail while the Russians wer still upon the Dunajec, was as follows. Gen. Roberto Brusat with the I. Army was to conduct a limited offensive against th Trentino salient, with the object of shortening the line an securing strong defensive positions. Gen. Nava with the IV. Army was to push N. from Cadore to threaten the enemy con munications in the Pusterthal and cooperate in an advance fron Carnia. This advance was to be conducted by a separate fore under Gen. Lequio, consisting mainly of mountain troop which was to move in the direction of Tarvis. The II. and II Armies, under Generals Frugoni and Zuccari respectively, wer to cross the Isonzo and attack E. with all speed. A large number of troops, with units brought up to war strength by the recall of several classes, had been in the neighbourhood of the frontier for many months. They were not in sufficient strength for attack, but were aligned with the object of covering mobilization; fo the enemy was already fully mobilized, and the prospect of sudden attack on his part had to be considered.
As the discussions between Rome and Vienna gradually le towards the final break, the Austro-Hungarian command pre pared for defence. In addition to the strong permanent work already existing on the main routes, " barrier lines " we constructed in the valleys and on the open sectors of the front many of the fortress guns were removed and placed in we concealed positions, and wire was lavishly employed. At the end of April the Austrian covering troops, under the command of Gen. von Rohr, numbered about 80,000 infantry, 1,400 cavalry and 54 batteries, in addition to fortress troops and guns. Two divisions under Gen. von Koennen-Horac were stationed in the Trentino; one division under Gen. von Langen watched the approaches to Carinthia; two divisions under Generals von Boog and ron Kuczera were upon the middle and lower Isonzo respec- tively, or, rather, E. of the river, in the mountains, on the Carso and about Gorizia. These divisions were improvised forma- tions, with a considerable proportion of second-line troops and volunteer battalions.
