May 29, 1915. 
L A N D AND W A T E R 
below such a flanking movement would have to 
be abandoned by tlie enemy. But, with normal 
prcyision upon the part of the enemy, such a move 
would be impossible. On the west tlie Stelvio 
Pass — (1) on the foregoing sketch — is quite im- 
pas.sabie against a most moderate defcnsiAc ; a true 
mountain road and still blocked with snow. The 
Tonale (2), soutli of the great frozen mass of the 
Ortler, is in no better condition. There is an 
easier pass (3) only a fevv' miles to the left of 
Lake Garda, but it is still a single mountain road 
through a defile, and on either the main Adige 
Valley or up the Arco ^'alley from Lake Garda 
there is no room for any deployment. The railway 
negotiates the \'al Sugana over the pass at Tezze 
(4), but there is no true passage here of any con- 
siderable force. 
There is. indeed, only one avenue up the 
Trentino, which is that of the main Adige Valley, 
and an advance up the Adige Valley would be the 
mere forcing of one narrow road. iSow we know 
how immensely powerful the modern defensive is. 
and on the top of that the town of Trent, a couple 
of days' march from the valley, is a strong 
fortress. 
It may fairly Ije said that the Trentino is for 
the Austrians a defensive asset of the first 
quality, and that if Italy can force it she will 
have achieved a task which military opinion 
throughout Europe regards as one of the utmost 
difficulty, and will correspondingly raise her 
prestige. 
But the forcing of the Trentino. supposing 
any appreciable strength lay behind, would be 
barren enough of result. The valley of the Adige 
le^ids only, like all those tributaries of the Po, to 
the main chain of the Alps, and though the 
Brenner Pass (which is its conclusion across the 
main ridge) is the easiest of the great Alpine 
highways and the historic road over the moun- 
tains, modern defensive opportunities make it 
impregnable to any force save one overwhelm- 
ingly superior to the defenders. 
11. The second sector of this front is that 
of the Carnatic Alps. These form a ridge quite 
unbroken save at the Pass which leads from the 
Fella Valley past Pontebbo, to the sources of the 
River Save. That gate, though high, is crossed 
by a railway, and is, like the Brenner, one of the 
historic roads of invasion; it was Napoleon's 
road; but it is far too narrow for an attack in 
Here again then, the defensive has an over- 
whelming opportunity, which nothing but sheer 
exliaustion or crude incompetence would forego, 
and between this Pass and the Upper Adige 
Valley, a niatter of ninety miles, there is the high 
Carnatic Alpine wall, which no large body of 
men could surmount against a defensive worthy 
of consideration. 
III. There remains the tlilrd sector of the 
frontier, which runs down south again across the 
force by armies upon the scale engaged in this 
great war against any adequate modern defence. 
bulwarks of the Julien Alps to the Plain of 
\'enetia, and across that plain to the sea. 
In the mountains where the frontier follows, 
for the most part, one of the lateral spurs of the 
main Alpine chain, the conditions still ai'e those 
of the first two sectors, but when the line comes 
down on to the lower Wei and towards the plain, 
the defensive has, indeed, no advantage ajjparent 
upon ordinary maps. But look at the district on 
any maps of fairly large scale, and you will see 
the way in which the frontier has been drawn so 
as. to protect the all-important Istrian Penin.sula 
from invasion, in a fashion which deliberately or 
accidentally has given advantages to the 
defensive. 
The frontier first follows the Piver Juarli, 
which has, as it appi'oaches the plain, defensive 
positions all along its eastern, or Austrian, bank. 
There is only a tiny front on this frontier, of less 
than twenty miles (nearer fifteen), upon wliich an 
insufficient force could deploy, and though the 
coimtry behind it is not mountainous, there comes 
immediately parallel with the frontier, and clo.se 
behind it, the defensive line of the Isonzo, with 
hill country following everywhere the eastern 
bank of that river. 
Now, this, the only vulnerable sector, deijiands 
closer examination. 
The political frontier issues from the hill 
country in front of Cividale at the village of 
Mernico. It then continues dov.'n the valley of 
the Juarli. There it cuts across to the Nati.sone, 
passes imniediatcly in front of Palmanova, and 
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