August 2.2, 
1914 
LAND AND WATER 
to defend itself. For the line C— D lias nothing to oppose to this 
flanking movement but the few men near its extreme end. 
Observe that, in order to meet this threat u-Jtatever C— D 
doea will weaken him. Supposing that when he sees the pro- 
longation of C— D's line at E— F, he stretches his o^s-n hne out 
to face that prolongation, then he makes 
his hne tlunner and leaves it in peril of 
being pierced by superior forces opposed 
to it at every point. 
Suppose he turns round two of 
hia sub-divisions M, M to face and 
hold off the flanking movement, as in 
Plan XL, then he leaves the other 
four sub-divisions N — 0, N, 00, faced 
by superior forces {nx) which may pierce 
them or overwhelm them. 
As a fact, what usually happens 
when a flanking movement has been 
executed with sufficient promptitude is 
tliat it begins to turn into Envelopment. 
That is, the inferior force C — D bending 
back first on one wing M, M, to avoid 
attack from one side, leaves itself inferior 
as against the original force A — B opposed 
to it. That original force then begins a 
flanking movement on the other wing 
before which its inferior enemy again 
bends back (0, 0), and by that time the 
communications of 0— D are in danger 
of being cut. (Plan XII.) 
If they are cut and the envelopment 
is complete, you get a result such as that 
of Sedan, in which the enveloped Army being no longer able 
to receive food or missiles, is compeUcd to surrender. Some- 
times, before the process is complete, you get a result Uke that 
of Waterloo, where the Army threatened with envelopment 
breaks under the strain, loses all unity and cohesion, and is 
routed ; that is, turned from an organised unity into a chaos. 
It is evident that in all these cases the presence of superior 
numbers is, other things being equal, the decisive factor. It has 
been well said that the art of Strategy consists in getting two 
men to a place where only one man is ready to meet them. 
But it does not follow by any means that of two national 
armies that which is the larger is certain to succeed. 
What is meant by the aphorism is that wherever a particular 
battle or general action is fought, wherever, as another term goes, 
things are brought to a Decision, superiority of numbers on that 
particular field at that particular moment, is the chief deciding 
factor. Thus, Napoleon in the Campaign of 1814 fought against 
superior total numbers ; but he kept the various bodies of his 
enemies separated, and attempted to be, and often was, their 
superior in each particular engagement. 
Now it is in connection with this truth, that not superiority 
in the total numbers ultimately available, but the superiority 
p L. A N rs. 
PLANVSi 
c 
A 
[} 
"" 
D- 
- 
T> 
B 
t«NE5 OF C0MMUNICATfO^f 
fci- 1 ..^j . ..1. ;> .. i 
in the ntimbers present on the decisive spot and at tlie decisive 
tnoment decide an action, that we can best appreciate the meaning 
in war of the Ohotade ; and of Fortification, which is (in most of 
its uses) no more than a particular case of the Obstach. . 
When we talk of an Obstacle — a river, forest, marsh, or hilly 
country— presented to the strategical advance or offensive of au 
army, we do not connote by that term what is connoted by i» 
in civil affairs. We are not considering the mere difhculty of 
passing it. For the unhampered army of a civilised people can 
PLANT X 
l.\T*t^ tf COMMUNICATION 
.. > .«■! I !■■; n i > 
D- 
D- 
[} 
r-a 
pass any such obstacle if sufficient time be allowed it. Wlut 
we connote by it is the Factor of Delay. 
Here (Plan XIII.) is a river A — B. Two forces, E the lesser. 
cb cb ^^ 
nD- - 
LINES CP COfAMuNtCATiON L-" m 
f 
and F the greater, are in presence. A third force G is coming 
np to effect its junction with £. If it succeeds in doing so the 
combined force G-J-E will be greater than its enemy F. The 
P LAN xn 
M H 
N 
HNE5 OF COM MUHICATIOM 
. ^J 
^l 
'.v^ 
^ 
river A — B is an Obstacle. It is an Obstacle in favour of E, wlio 
is on the defensive, and against F, who is on the offensive. But 
its only value to E is in its power of dclayivrj F while G comes up. 
If there were no G to come up and help E the river could not 
