The following notes are based on the observations of a British staff officer
who made a careful study of Japanese tactics in Burma.
* * *
Japanese defensive tactics are offensive and mobile. Small or large
fighting patrols operate on the flanks of advancing troops, and, recently, in
the Arakan, a company moved around to our [British] rear at
night, and, occupying a defensive position, disrupted communications until
the Japanese were attacked and destroyed. A Japanese source states that
passive defense has the disadvantage of making it easy for the British to
build up their strong firepower.
An interesting feature of all Japanese defensive positions so far examined
is that the Japanese invariably go for high ground, and have no qualms about occupying
the crest of a hill, even if it is accentuated by a pagoda. Automatic weapons are
often located on the crest.* Positions vary in strength, from a single sniper up a
tree, to a strong defended locality containing about a hundred men armed with all
the usual infantry weapons plus antitank guns and possibly a flame thrower.
Isolated combat posts are often found 300 to 1,000 yards in advance of the
main line of resistance. In some instances these covered important lines of
approach, and were obviously intended to be held to the last.
Although the Japanese have not used much wire in Burma so far, it is clear
from aerial photographs that they are constructing both double and single fences,
with and without aprons. It should be remembered that the wire may be in
the rear as well as in front of the enemy positions, making it necessary for the
assaulting troops to cut their way out on the far side of the position after they have
captured it. In addition to fences, the uprights of which are constructed with local
wood, loose wire is sometimes put down in bushes in front of a position.
The Japanese seldom open fire from their defense areas unless an assault
is actually going in. The job of dealing with reconnaissance parties which approach
too close is left to snipers in the branches or under the roots of trees, or even to
the small detachments which are occasionally found in advance of the main
position.* Nothing is done which might give away the position of an automatic weapon. In
fact concealment is often of such a high standard that it is extremely difficult to
say whether a certain small hill top is actually occupied by the enemy or not. You
seldom see a Jap, and you seldom see movement.
The enemy will hold his fire until the assault is 30 to 50 yards from the
locality. Fifty is about the maximum. On one occasion at Rathedaung a fixed
line for a machine gun was only 10 yards from the parapet of the Japanese trench.
The third important point in the Japanese conduct of the defense is that if
they have had time to roof and otherwise protect their light and medium machine
gun positions, they have no qualms about bringing down their own mortar and
grenade discharger fire upon them. The Jap grenade discharger is
really a 2-inch mortar (50-mm) firing a special shell. Thus, any assault party which stays
too long on a pill box will draw fire from weapons in the rear; in fact, a captured
position must generally be regarded as an unhealthy position to stay in.
Another not invariable feature of Japanese defensive tactics is the immediate
counterattack. This has seldom been a big affair. The charge is preceded
by a shower of grenade discharger shells and made with automatic weapons -- probably
one or two Model 96 LMGs. This attack may be made from the rear of
a small area, the forward trench of which may have already been captured. It
may also be made from a neighboring area, but this is less likely. In any case,
its strength lies solely in the speed with which it comes in. It is usually launched
at five, or at the most ten minutes after the area has been penetrated.
*In Guadalcanal and Bougainville, the reverse slopes were defended, and seldom, if
ever, were weapons found on the crest. On Bougainville reconnaissance parties
were fired upon with light machine guns and mortars.