Evening star., 1943-10-01
The River Crossino:
ACIussic Test
By Maj. George Fielding Eliot.

afford one of the greatest examples in
history of the attack and defense of
river line, it may be useful to examine
some of the principles affecting this
type of operation.
Like all modern defense, the defense
of river line must be mobile. The
real heart Of the defense is counter
attack. The river must be used to en-
able counterattack to take place under
the most favorable circumstances, rather
than be regarded as an inflexible bar
rier every yard of which must be de-
Tended. If the river be regarded only
as a formidable trench in a system Of
defense in depth,p writes Capt. Cyril
Falls ("The Nature of Modern warfareD
1T may prove extremely valuable, but II,
on the other hand, the system of de-
fense be based entirely on the river, it
will fail" This was written in l94l;
more than a century before, the Baron
de Jomini expressed the same thought
in a different way: The important
thing is to have the course of the river
watched by bodies of light troops, with
out attempting to make defense at
every point. Concentrate rapidly at
the threatened point, in order to over
whelm the enemy while a part only of
his army shall have passed
That is the basis for the defense Of
a river line--to catch the enemy. In the
classic phrase, "aStride the river and
to wipe out the part of his forces which
have passed, while the remainder is un-
able to get across to help them. The
selection of the proper moment for
commencing this counterattack," notes
Col. Foertsch of the German general
staff ("The Art of Modern Warfare), is
a difficult problem. If the forces that
the adversary is allowed to bring over
are too strong, there is danger of their
breaking through the defense. If they
are too few, however, the blow will land
in the air and lose its effect
In forcing crossing the attacker
will proceed by stages First he will
ferry across detachments of specially Sc
lected infantry and pioneers in assault
boats and other craft tne assumption
is, OF course, that bridges have been
blown up and fords blocked. When
farther bank, light pontoon bridges can
be thrown across and we have the begin
ming of a bridgehead The next step is
to widen the bridgehead by seizing
better defensive positions, which VIII
protect the crossing point from small
arms fire or direct ground observation.
This in turn enables more troops to
cross and the bridgehead is further en-
larged so as to protect the crossing
points Cby this time there will be more
than onel from artillery fire. If this
can be accomplished, the final step is to
so deepen the bridghead as to make the
maneuver of considerable forces posi-
BILE within it. Only then can it be used
for the development OF a full-sCale at
tack Obviously, as Col Foert5Ch points
out. the selection of the exact moment
for countera tack against these pro-
ceduyes is a matter which calls for the
most careful judgment and the most
accurate estimate of the situation by the
defending commander. II is choice IN
which he must consider, not only what
the attacker is doing. but also the avail
ability of his own forces for counter
attack at any given moment. Military
history is full Of lost opportunities re-
sulting from having waited for few
more regiments to come up in order to
make sure; it also contains the record
of many bloody repulses from having
launched attacks with insufficient
forces, so that when the first checks
came there were no reserves to push
the attack home.
The influence of a good tactical air
force on river-crossing operations is
perhaps more in favor of the defense
than the attack Airplanes can act to
a great extent as sort of mobile artll-
lery, giving cover for an attacking force
which it might not be able to get from
guns: but the attacker is greatly de-
pendent on material structures-bridges
the material for which must be drag
ged to the crossing sites and there con-
verted into actual bridge construction.
The movement of this material, as we'll
as the bridges during and after con-
struction, are favorable targets for the
defending aviation, and continue to be
so even after the third stage of the
widening of the bridgehead has been
concluded and the bridges are no longer
under the fire of enemy artillery. More
over, one of the most important features
Of an attack on river line is the at
tempt to gain tactical surprise by making
feints toward various points along the
river, thus seeking to deceive the de-
fender as to the chosen point for the
main crossing and keeping his forces
scattered until it Is too late for de-
cisive concentration. This is far more
difficult to do when every move is
vieilantly watched by an active Defend
ing air force which will be able to
determine. from the location and move
ment of the huge bridging trains, which
of the discovered moves of the attacker
is serious and which are feints.
OF course an attacker will endeavor
to effect a crossing at more than one
place-especially in an attack on line
so long as that of the Dnieper from
Orsha to the Black Sea. The essence
of successful attack like that of defense
is notwithstanding the final decisions
back until the last moment in order to
take advantage of changing circum-
stances. But once the troops for the
main attack are in motion, the die is
cast and the attacker must stand or fall
on the result. The defense or the
attack of a river line, affords some of
warfares greatest opportunities for