April 1 8, 191 8 
Land & Water 
Battle of the Lys : By Hilaire Belloc 
THE present action of the enemy in Flanders is 
connected thus with the campaign as a whole : — 
The enemy had planned to make his great 
attack in the West upon March 21st. He had 
concentrated for that object a far greater weight 
of artillery than had ever been gathered before. Out of a 
total force of not quite 200 divisions available for every kind 
of service, he marked down actually over one-half, and those 
tlie best, for a particular object — to fail or to succeed in 
which would probably decide the war. 
What that object was is now as clear as daylight. Now 
that we know he was prepared to put in one hundred divisions, 
and now that we have seen the continuous expenditure in 
men which he deliberately permitted, it is mere nonsense to 
speak of the great attack of three weeks ago as but one of 
two or more plans. It was as single and as decisive a moment 
as ever there has been in military history. His aim was to 
tear through the British line as near to its right as possible, 
where it joined the French ; to pour through the gap, restore 
a war of movement — for which he had been training close 
on a million men first and last for months — and by his 
rapidity and the superior value he claimed in such a war of 
movement to thrust the British Army up north with blow 
upon blow towards the sea, daily reducing its value as an 
opponent, and rapidly thus achieving a decision. 
There existed, as he well knew and perpetually discussed 
in his Press, a large AlUed force free from the line and ready 
to act as a mass of manoeuvre. That was his risk. But his 
insurance against that risk lay ii^the calculated rapidity of 
his action against the British Army when it should have been 
torn asunder from its Allies and should be compelled to what 
he conceived would be its increasing confusion in an open 
war. The British Army had been created during a period of 
siege war ; once manoeuvring at large, he thought himself 
its master. 
We know what followed. It was the unexpected for both 
sides — much the most general happening in war. He did 
break through. He did restore a war of movement. But 
he just did not succeed in maintaining it. The flood began 
to pour through, but was rapidly dammed. Its full energy 
was maintained for nearly a week. By the tenth day — that 
is, by Easter Sunday — it was slowly gaining in a few last 
waves, but had already come up against a sufficient bank of 
resistance. In a day or two over the fortnight it was defin- 
itely held : for the last great assault of April 4th failed 
with murderous loss. 
A number of subsidiary advantages which the enemy had 
gained were the elimination of a quantity of Allied material, 
the threat to one great line of communications, etc. But on the 
debit side there was far more, and the balance was against 
the German. He had lost upon the balance, far more men 
than his equal opponent, just in this phase Of the war when 
the whole thing is a struggle of each to reduce the effective 
numbers of his foe. Ahd he found himself upon an abomin- 
able line, with high ground against him everywhere, with a 
huge vulnerable flank of over 20 miles on the south, and 
more than half as much again to hold in mileage without 
prepared defences as he had before he began. 
The price of all tliis failure — for it was a failure — was the 
eUmination of a great part of the margin which he had free 
for attack over and beyond what was necessary to hold his 
line. 
He had no option but to make a new, a separate movement, 
while the continued holding of their hands by the Allies 
permitted him the initiative of risking these continued losses. 
tie might make that movement wherever he chose. He 
might have made it, for instance, upon any part of the great 
new Montdidier salient. He might even mal;e it where his 
last pressure had ebbed away on the westernmost point of 
that advance towards .'\miens. But even so, it would have 
been a second and a separate effort, and would have had to 
be made with less strength tharj the first, for tlie simple 
reason that less strength remained to him. 
He decided, as a fact, to make it upon the northern sector 
of Lille ; acting thus as he has always acted, to wit, in copy 
of his own past ; for to strike alternately and to create 
double salients was his method all through his Russian 
campaign and remains his gospel for his last effort in the 
West. The date April 9th was chosen for this second effort, 
and, as I have said, the sector in front of Lille and an ultimate 
development of 20 miles of front there— less than half that 
of his first effort — was his choice. 
The reasons for which the enemy chose this particular 
sector of attack may be tabulated as follows : — 
(i) It was as far north — that is, as distant from hi^ first 
main battlefield and point of pressure in front of Amiens-^ 
as could usefully be chosen to impose by its distance a maxi- 
mum strain upon Alhed reinforcement. Had he struck yet 
further north he would have had high ground in front of him 
and north of that again flooded country. 
(3) Striking thus not in the extreme north, but in the 
north of the centre he could threaten the communications 
of, and therefore, if he were immediately successful, would 
destroy all the British forces that lay between his point of 
attack and the sea. 
(3) He knew that there were here not a few divisions 
sent to redress, under the conditions of a sector long quiet, 
the strain and loss which they had suffered elsewhere ; and 
he knew in particular that one division consisted of what he 
was pleased to describe as second-class troops. 
(4) He enjoyed a remarkable superiority in railway com- 
munication. 
This point is of such importance that I would beg my 
readers to consider it in detail. 
Railway Communications 
If the reader will turn back to Map I., and look at the 
sinuous Une of the front as it stood from the Amiens-Arras 
sector to the sea at Nieuport upon April 8th — the eve of the 
new offensive — he will perceive what admirable oppor- 
tunities for concentration upon Lille the railways, double 
and single, in the hands of the Germans present ; and, at 
the same time, how perfect is the continuous line of lateral 
communications from Ostend southward through Lille and 
Douai and Cambrai. The whole is a double-line railway, 
with the exception of the strip between A and B. This in 
the past four years he must surely have doubled — no very 
difiicult task, for it runs through flat country. When I 
speak of this part of the hne as single, I am entirely depen- 
dent upon information as belated as that of 1913. Unless 
I am mistaken, the section between A and B was a single 
line in that year ; but all the rest of the lateral communica- 
tion was a double track, and we observe that it exactly 
follows the line of the front all the way down, and at a suffi- 
cient distance from that to be continuously available, 
in spite of the heavy work done against it from the air. 
Upon Lille itself there converge no less than five great main 
lines of double track, probably increased by this time, as 
I have just said, to six. There are, of course, large railway . 
works and sheds, innumerable sidings, and all the oppor- 
tunities for concentration afforded by a great town. 
Now contrast this with the corresponding communications 
upon the Allied side in reference to the sedqr of attack. 
Here also there is a lateral line : Dunkirk-Hazebrouck- 
B6thune-St. Pol-Amiens. But it is devoid, in the neighbour- 
hood of the sector opposite Lille, of any great centre of 
concentration — the best is the comparatively small though 
exceedingly important junction of Hazebrouck. It has — or 
had— a very considerable sector of single line ; it is indif- 
ferently parallel to the front, approaching it far too close at 
Bethune, receding too much from it elsewhere. What 
Hazebrouck means, by the way, we shall see later on, when 
we consider the field of action in detail. The alternative line 
behind the nearest lateral communication is the great main rail- 
way Amiens-Calais ; the hilly country between, coupled with the 
necessity of linking up the ports, has thrust this line far back. 
Added to these advantages in railway communication 
which the enemy would enjoy if he chose this Lille sector for 
his second offensive was the fact that, so far as railways 
were concerned, he was virtually working upon interior lines. 
Let me explain this point. 
If you are working within a large concave, such as that of 
.\-B in the accompanying diagram, and if both your lateral 
communication C-D and that of your opponent E-F are 
each roughly parallel to the front, it is clear that you can 
move your troops more quickly than your opponent can 
move his. You can bring a particular unit of yours from 
D to C in a little more than half the time that he can bring 
a unit of his from F to E. That is called the strategic advan- 
tage of working upon interior lines. There is no sucii advan- 
tage, of course, when the concavity is small and cramped, 
but the advantages are obvious when it is large. 
Now this advantage of interior lines exists in another form 
