The Intelligence Bulletin for November included a
section on the early fighting in the Solomon Islands.
Since that time additional reports have been received,
giving much more information about Japanese tactics
and weapons. All the reports are from officers and
enlisted men who took part in the operations. In presenting
the new information, duplication of data given
a month ago is avoided as far as possible.
Our observers are placing renewed emphasis on the
extreme cunning, treachery, fanaticism, and brutality
practiced by the Japanese. Several instances of these
practices are given in this section. It is the belief of
our observers that our troops must take nothing for
granted in dealing with the Japanese and must ever be
alert for any possibility.
The Japanese are firm believers in securing detailed
intelligence about their opponents, and have been very
successful to date in this aspect of operations. They
have prepared maps of great detail, even of jungle
areas. They have had considerable success in radio
interception, taking good advantage of the information obtained.
One Marine patrol came upon a 25-man Jap patrol
in the Solomons and accounted for at least 18 of the
enemy. The Marines reported that the Japanese were
exceedingly well equipped. They carried portable
radio transmitters and mapping and sketching equipment.
Our interpreter read captured messages indicating
the presence of a landing force and including
other valuable information, which was used by our
troops in dealing successfully with the Jap force.
Our observers continue to stress the infiltration tactics
of the Japanese in jungle warfare. Individual Jap
soldiers, with light but very effective equipment for independent
combat, crawl through jungles so thick that
it would appear impossible for a human being to penetrate.
Yet for miles they wriggle their way through
on hands and knees, or on their stomachs--taking several
days, if necessary. Once behind our lines or on
our flanks, they often get together and form large and
effective patrols, which cut off or wipe out our outposts.
They seek to weaken our main positions and make us
vulnerable to an attack in force.' Often these infiltrating
groups, which include snipers, are assisted by
covering fire from heavy machine guns, automatic rifles,
At night, the infiltration tactics apparently are aimed
at creating confusion in our ranks and destroying our
automatic weapons. (This bears out the importance of
our training doctrine which calls for riflemen to protect
our automatics from the front, flanks, and rear.) At
times Jap groups tried to stampede our
troops, shouting "American Marines, you die!"--which apparently
is a battle cry. Sometimes these groups were so small
that their members must have realized that they were
attempting a suicide venture. On one occasion, a
Japanese lieutenant and two privates charged a Marine
battalion headquarters, shouting their battle cry.
One of them bayoneted a Marine sergeant as he sat on
a stump. The three were immediately overpowered
and killed—they must have known in advance that the
charge would lead to their death.
In many respects snipers caused the Marines more
trouble than any other single factor. Sniping is tied
up very closely with offensive infiltration attacks, and
also with nearly all the defensive efforts of the Japanese.
Normally, the snipers tied themselves in the tops
of trees, where they were well camouflaged. Often, however, they
were found in nearly every place where they
could hide--such as behind logs and in bushes, caves, or
ravines. At night, several Japs leapt into foxholes
occupied by Marines and were killed because they could
not give the password.
Usually the snipers waited until their target had
passed and then shot him in the back. They seldom fire
on individuals in movement. This is why our troops
now take cover at once when they halt.
The main function of the snipers apparently is to
harass and confuse our forces, distracting them from
their main effort. "Our troops found it most undesirable
to allow the assault echelon to become involved
with snipers on the flanks and rear," said one observer.
"In a number of instances, it was found practicable to
bypass the snipers with the assault echelon and let
small follow-up patrols clean them out later."
After shooting snipers who had tied themselves in
trees, our troops had trouble in getting the bodies down.
The problem was solved by having a tank knock the
tree down, or by placing a ring of dynamite around the
base of the tree and blowing it up.
Japanese prisoners said that normally each of their
infantry squads included two snipers, who ordinarily
tied themselves to tree tops in the area occupied by the
Nearly all conceivable types of camouflage have been
used by these snipers. Some in the Solomons wore
fiber cloaks, which blended perfectly with the coconut tree trunks.
The snipers, as well as other Jap troops, have unbelievable
patience and endurance. The Marines had numerous cases
where their enemies crouched or lay in
one position, highly camouflaged, for as long as 3 days just
to fire one shot--undoubtedly realizing that they
would be killed immediately afterwards. As an illustration, one
of our men at Milne Bay (New Guinea) relates the following:
"A Jap, camouflaged as a tropical bush, crouched for
2 days without moving, on the edge of an Australian
jungle outpost, to learn the names and nicknames of
members of their detachment and their particular
habits. One day, in a perfect Australian accent, he
called out, "Say, Bill, where are you? This is Alf." When
Bill shouted in reply, the tropical bush suddenly
arose and shot him dead. The bush immediately
dropped back into the foliage. The sniper was
wounded only after the area had been completely raked
by machine-gun fire. The Jap, wounded severely, told
his story. He had fully expected to die after the
The Japs have been using for communication a large
number of very efficient, light-weight, and portable
radio transmitters and receivers, as well as flares, Rising
Sun flags, and bird calls.
Red and white flares, as a rule, have been used to
outline their front line and also to signal the arrival of
a unit on our flanks. The flares have been extremely
useful to our forces, who have successfully raked the
areas with artillery fire.
Rising Sun flags have been tied to trees to inform Jap
aviators of the front-line positions of their troops. The
flags also proved to be valuable aids to our aviators, who
bombed the indicated areas with excellent results.
The bird calls apparently were used as a night signal
to inform commanders as to the whereabouts of their
various sub-units. Sometimes the calls also may have
been used to confuse our troops.
Antitank weapons used by the Japanese include what
is believed to be a 47-mm gun, grenades, and gasoline.
At times, when our infantry was not within supporting
distance of our tanks, gasoline was thrown on the latter
and set on fire. In at least one case, the Japs jammed
a driving sprocket before throwing on the gasoline.
Grenades apparently are thrown at the tanks to set
them on fire after gasoline has been thrown on them, and
to hit openings through which the crews can be injured.
It is known that the Japanese have been trained to
throw shelter halves over the slits of tanks in close
country and then attack them with magnetic bombs or
other hand weapons.
The antitank gun made a hole slightly larger than
our 37-mm shell, and observers are reasonably sure that
the weapon is a 47-mm gun. This is entirely probable
since the Germans have a 47-mm antitank weapon. One
shell, apparently fired from a distance of 100 yards,
penetrated the right forward side of an M-3 turret and
hit the opposite turret wall, where it exploded. Filling
from the shell ran down the wall and began to burn
with a yellow flame and bluish smoke. The driver
stated that fumes from the substance were sharp and
stifling, and caused his mouth to dry and pucker. The
flame was difficult to extinguish. Reports do not indicate
whether the tank hit was a light or medium M-3;
but at a range of 100 yards the turret of a light M-3
could be penetrated and it is possible that a medium
tank turret could be penetrated at this range.
To date, there has been no evidence that the Japanese
actually have used magnetic tank grenades in the
Solomons, although some of these grenades have been
captured on Guadalcanal.
The Japanese go to extremes in the employment of
deception. Many of these illustrate their treachery and
lack of scruples. The following is a partial list of the
deceptions used in the Solomons:
(1) While an American doctor was dressing the
wounded leg of a Japanese, the Jap pulled a knife and
(2) Several Japanese nurses walked up to our
wounded with their arms raised, and, when close at
hand, they threw hand grenades among the soldiers.
(3) Two or three days after the Marines landed in the Solomons, a Japanese
captain of a labor battalion walked into a division headquarters and
surrendered. He said his entire battalion would surrender and could
be brought in if a detail were sent out to their position, which was
some distance down the beach. A colonel and a detachment of 20 Marines
were sent in a landing boat to the specified position. As he and the
detachment stepped ashore, they all were killed except a sergeant, who
was wounded. He returned to headquarters. A Marine force rounded up
the Japs shortly afterwards by attacking from the rear. Instead of
being a labor battalion, the Japanese turned out to be a special-weapons
detachment, 200 strong.
(4) Japanese-employed natives often informed our
headquarters they had groups of wounded Marines, and
offered to guide our rescue forces to the men. We
learned from bitter experience that these were Japanese ambushes.
(5) The Japs learned the names of some of our officers,
and, during darkness, would call out to them in
excellent English in order to locate them, or to issue
withdrawal orders to them in English.
(6) They also used the old trick of setting off firecrackers
to distract our troops, and to give the impression
they were being attacked by large forces.
(7) Among their tricks, the Japanese painted with
red crosses all the buildings they occupied, believing
that our forces would not bomb the marked buildings
because of our high ethics. One such building, when
bombed, turned out to be an ammunition dump.
(8) On one of the small islands taken in the Solomons, the
Marines ran into some tough fortified opposition
and called for 1,000-pound demolition bombs. The
group air commander of an aircraft carrier was directed
to bomb the island, and, on his way to the island,
he received a counter-order stating that the Marines
had now gained possession of the island and that he
was not to drop any bombs. "Authenticators" (pass
words) had been worked out among the pilots the night
before, using the pilot's nickname. The voice countermanding
the order was unable to furnish the correct
authenticator and the bombing was carried out. The
commander discovered that the voice on the radio was
that of a Jap, who was speaking English and using a
perfect American accent.
Instead of using sandbags as part of their defensive
setups, the Japanese used bags made from rice straw
and filled with dirt. Apparently, unhulled rice seeds or
seeds of a similar plant were planted on the top portion
of the sacks, because they were covered with a green
growth. This blended the defensive positions with
The Marines found from experience that our grenades
and mortar shells should be painted green. When
they are painted a light color, they can be seen easily
at night. In several instances, the Japanese were able
to pick up the grenades in the darkness and throw them
back before they exploded. Our troops are finding it
best to remember that the time delay of our grenades
is between 4 and 5 seconds, and that the length of time
the grenade is held by the thrower should be governed
by the distance between him and the enemy. It should
never be held more than 2 seconds.
h. Night Operations
Japanese troops are particularly well trained in night
operations, and they prefer night attacks to those during
daylight. Invariably, they try to work small groups
to our flanks and rear in an attempt to cause panic
and destroy automatic weapons.
In making night attacks, the Japanese select clearly
defined terrain features, such as ridges and streams, for
successive objectives. The attacks generally are delivered
on a narrow front and uphill whenever possible.
By attacking from low ground, the Japs try to conceal
their forces and at the same time silhouette ours
against the sky line.
A series of red flares (similar to our Roman candles)
have been used by the Japanese platoon leaders to indicate
the direction of advance. The signal for the
assault has been a flare fired to hang over their objective.
In several instances, they placed smoke on Marine
positions and then charged forward, shouting "Gas!"
in English. Some Japs who had infiltrated to our
flanks and rear shouted "Withdraw!" when the frontal
attack began to develop in force. The groups that were
to make the main assault talked and sang during their
approach, to distract our attention and facilitate and
cover the movement into position of the infiltration groups.
The Japanese used their automatic weapons extensively
at night, but did very little firing with rifles. In
attacking, their fire usually was high, apparently to
avoid hitting Japs who approached our lines to lay
down grenade barrages. An assault generally followed
Our automatic weapons, mortars, and artillery were
excellent in breaking up night attacks.
Against our landings on the various islands, the Japanese
used mostly rifle and machine-gun fire from dugouts
and other prepared emplacements, supported by
the inevitable snipers. Our preparatory bombing and
shellfire had caused few casualties, because the dugouts,
shelters, and trenches afforded the Japs excellent cover.
The preparatory fire kept the enemy under cover while
our first and second waves landed. The fighting developed
into a series of attacks on dugouts and the
destruction of snipers in trees. Use of improvised
flame throwers and dynamite at dugout entrances
proved the most effective way of dealing with the
(1) Fighter planes.--Japanese fighters come in from
all angles when attacking our bombers. The Japs press
their attacks furiously when our bomb-bay doors are
opened for a bombing run, approaching individually
from many angles but attacking at the same time.
(2) Bomber planes.--The bombers used by the Japs
are of a twin-engined type similar to our B-26. They
usually bomb from about 25,000 feet.
(3) Antiaircraft fire.--Antiaircraft fire from Japanese
ships is usually inaccurate except from battleships
and heavy cruisers. All ships fire a barrage overhead
when our bombers are making runs over them.
(4) Direction Finders.--The Japanese are now using
radio direction-finding equipment in the Solomons to
detect the approach of aircraft. Their equipment has
not been very effective to date. Antiaircraft guns
sometimes do not fire until our bombers have made their
first run, and sometimes our bombers arrive over the
target before the Jap fighters are able to take off.
(5) Identifications.--Observers feel that training in
the identification of aircraft (and also of ships) cannot
be overemphasized. They believe that actual service in
the combat area is necessary to perfect this training.
The Japs seldom retreat or surrender. All those captured
invariably ask, "When are we going to be killed?" Upon
learning that they are not going to be killed,
they beg never to be exchanged and sent back to Japan.
They believe that it is a national disgrace for them to
surrender, and that they and their families would be
shunned for the rest of their lives in Japan.
The Japanese attitude toward surrender was illustrated
in an incident that occurred during the first day
of the operations in the Solomons. Five crewmen of a
Jap bomber, shot down over Tulagi harbor, got into the
plane's rubber boat but refused to be rescued. A U.S. destroyer
approached, but one of the boat crew with a
gun held off the rescuers. When it was apparent that
the Japs were going to be captured by force, the man
with the gun killed his companions and was turning
the gun on himself when he was killed by machine-gun
fire from the destroyer.
Even in swamps and jungles, the Japs have learned
to live off the land. Usually they are sent on missions
with an emergency ration which includes rice and compressed
and condensed foods, such as dried fish and
vitamin tablets. They supplement this with jungle
food that our forces generally would not consider eating.
They are experts at knowing what is good for
them, and what is poisonous or not good to eat.
m. Medical Care
The Japanese appear to have thorough knowledge of
tropical diseases. They also know what poisonous bites
to expect, and how to treat them. They seem to have
some antitoxins, against jungle diseases, that we have
Most of the wounds our forces received in the Solomons
were not serious. Unless a vital spot is hit, the
Japanese 25-caliber weapons do not inflict bad wounds.
The Japanese have used two types of rifles, one of
6.5-mm caliber and the other of 7.7-mm caliber. The
6.5-mm rifle apparently has no telescopic sight; however, the
sight has an attachment for leading planes
during antiaircraft fire. The attachment can be adjusted
to the speed of the plane.
Japanese grenades are smaller than ours, and their
effective bursting radius is much smaller. The Japs
apparently realize the ineffectiveness of their grenades, because
they throw them at their opponents and promptly charge with bayonets.
The Japanese are using two or three types of mortars, one
of which is reputed to be fired from the thigh of
the gunner when he has assumed a squatting position. Later
reports, however, indicate that the weapon is
fired only while resting on the ground in front of the
These include a 47-mm antitank gun and a 77-mm gun. The
latter is believed to have been captured from
the British on Singapore Island. It is not known to
be an organic part of Japanese artillery. (This 77-mm gun
undoubtedly is either a 75-mm or a British 3-inch gun.)