August 22, 1D14 
LAXD AIS^D 
WATER 
to defend itself. For the line C— D Las nothing to oppose to tliis 
flanking movement but the few men near its extreme end. 
Observe that, in order to meet tbia threat whatever C — ^D 
docs will weaken him. Supposing that when he sees the pro- 
longation of C — D's line at E — F, he stretches his own Uno out 
to face that prolongation, then he makes 
his line thinner and leaves it in peril of 
being pierced by superior forces opposed 
to it at every point. 
Suppose he turns round two of 
Lis sub-divisions M, M to face and 
hold oS the flanking movement, as in 
Plan XL, then he leaves the other 
four sub-divisions N — 0, N, 00, faced 
by superior forces {six) which may pierce 
them or overwhelm them. 
As a fact, what usually happens 
when a flanking movement has been 
executed with sufficient promptitude is 
that 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 C — 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 compelled to surrender. Some- 
times, before the process is complete, you get a result like 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 gtJieral action is fought, wherever, as another term goes, 
things are brought to a Decision, superiority of numbers on that 
particular fidd at that partirular moment, u 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 
PL. A M IX. 
PLANCH 
c 
A 
_ 
{} 
- 
- 
D 
B 
tlNCS OF COMMUNtCATfOAf 
■■ ■ ■ ■ '■ -> * 
D- -I 
■ D- € 
D- 1 
DQ. fB 
in the numbers present on the decisive spot and at the decisive 
momeTit decide an action, that we can best appreciate the meaning 
in war of the O'ostade ; and of Fortification, which is (in most of 
its iwcs) no more than a particular case of the Olstacls. 
When we talk of an Obstacle — a river, forest, marsh, or hilly 
country— presented to the strategical advance or offensive of an 
army, we do not connote by that term what is connoted by li 
in civil affairs. We are not considering the mere difficulty of 
passing it. For the unhampered army of a civilised people can 
n- 
LJNE3 tf COMMUNICATION 
- " > ■ ' > 
D- I 
d[} -Ib 
pass any such obstacle if sufficient time be allowed it. What 
we coimote by it is the Factor of Dday. 
Here (Plan XIII.) is a river A— B. Two forces, E the lesser. 
ci3 cb "^ 
"tlMES «P CO 
nQ- 
liQ- 
StMUNlCATION U 
and F the greater, are in presence. A third force G is coming 
up to effect its junction with E. If it succeeds in doing so the 
combined force G-j-E will bo greater than its enemy F. The 
P LAN 301 
t- 1 N E 5 OF COMMUNICATIOM 
' ' " > . ■ ■ ■ 
^"D 
-^^ 
CP 
river A— B is an Obstacle. It is an Obstacle in favour of E, who 
is on the defensive, and agiiinst F, who is on the offensive. But 
its only value to E is in its power of delayinrf F while G comes up. 
If there were no Q to come up and help E the river could no» 
6» 
