The legitimate war, so to speak, in this region is a mountaineering war. The typical position is roughly as follows. The Austrians occupy valley A which opens northward; the Italians occupy valley B which opens southward. The fight is for the crest between A and B. The side that wins that crest gains the power of looking down into, firing into and outflanking the positions of the enemy valley. In most cases it is the Italians now who are pressing, and if the reader will examine a map of the front and compare it with the official reports he will soon realise that almost everywhere the Italians are up to the head of the southward valleys and working over the crests so as to press down upon the Austrian valleys. But in the Trentino the Austrians are still well over the crest on the southward slopes. When I was in Italy they still held Rovereto. Now it cannot be said that under modern conditions mountains favour either the offensive or the defensive. But they certainly make operations far more deliberate than upon a level. An engineered road or railway in an Alpine valley is the most vulnerable of things; its curves and viaducts may be practically demolished by shell fire or swept by shrapnel, although you hold the entire valley except for one vantage point. All the mountains round about a valley must be won before that valley is safe for the transport of an advance. But on the other hand a surprise capture of some single mountain crest and the hoisting of one gun into position there may block the retreat of guns and material from a great series of positions. Mountain surfaces are extraordinarily various and subtle. You may understand Picardy on a map, but mountain warfare is three-dimensional. A struggle may go on for weeks or months consisting of apparently separate and incidental skirmishes, and then suddenly a whole valley organisation may crumble away in retreat or disaster. Italy is gnawing into the Trentino day by day, and particularly around by her right wing. At no time I shall be surprised to see a sudden lunge forward on that front, and hear a tale of guns and prisoners. This will not mean that she has made a sudden attack, but that some system of Austrian positions has collapsed under her continual pressure. Such briefly is the _idea_ of mountain struggle. Its realities, I should imagine, are among the strangest and most picturesque in all this tremendous world conflict. I know nothing of the war in the east, of course, but there are things here that must be hard to beat. Happily they will soon get justice done to them by an abler pen than mine. I hear that Kipling is to follow me upon this ground; nothing can be imagined more congenial to his extraordinary power of vivid rendering than this struggle against cliffs, avalanches, frost and the Austrian.