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.

To go the Italian round needs, among other things, a good head.  Everywhere it has been necessary to make roads where hitherto there have been only mule tracks or no tracks at all; the roads are often still in the making, and the automobile of the war tourist skirts precipices and takes hairpin bends upon tracks of loose metal not an inch too broad for the operation, or it floats for a moment over the dizzy edge while a train of mule transport blunders by.  The unruly imagination of man’s heart (which is “only evil continually”) speculates upon what would be the consequences of one good bump from the wheel of a mule cart.  Down below, the trees that one sees through a wisp of cloud look far too small and spiky and scattered to hold out much hope for a fallen man of letters.  And at the high positions they are too used to the vertical life to understand the secret feelings of the visitor from the horizontal.  General Bompiani, whose writings are well known to all English students of military matters, showed me the Gibraltar he is making of a great mountain system east of the Adige.