Japanese Tactics in the Milne Bay Operations, WWII Tactical and Technical Trends, No. 26, June 3, 1943 (Lone Sentry)

a. General

The present tactics and techniques of the Japanese have been developed as the result of combat experience against active enemies under varied conditions and over many types of terrain.

As is generally known now, the Japanese are cunning fighters, skilled in the use of ruse and deception. They are well trained in the tactics of infiltration, especially in jungle and mountain country. Their favorite maneuver is the turning of an exposed flank. During the entire Milne Bay operation (see Tactical and Technical Trends, p. 28, No. 22 for previous reference to this operation), Allied flanks were never secure, because the Japanese had practically complete immunity by sea and so could make landings at any chosen point.

While it is true that the tactics employed at Milne Bay should be regarded as applicable to a particular terrain rather than as representing the normal situation in jungle warfare, yet the principles illustrated and the lessons learned are of general application.

b. Patrols

(1) Strength

From Japanese sources it is learned that in this operation the patrol strength for special tasks was one officer and six enlisted men, or one non-commissioned officer and three enlisted men. Normal night patrols numbered 18 men or more, while day patrols averaged from 6 to 10 men. In general, these patrols moved as a body and kept to the trails. Combat patrols were not employed by the Japanese for reconnaissance.

(2) Employment

Scouts made use of the thick jungle to approach our defense areas, or were left in position when the enemy withdrew from a night attack. In general, they would lie "doggo" and unobserved in order to get information to their troops. They allowed our patrols and working parties to pass unmolested.

c. Night Operations

The Japanese force relied almost entirely on night operations, for which it appeared to have been well trained.

There were no Japanese attacks by day and movement was limited. This might have been due to our complete command of the air. The main Japanese body rested by day with little regard for local security.

d. Approach March

During the approach march, the Japanese moved rapidly, in groups of 20 to 30, with little regard to flank protection. The main line of advance was the road or beach. Bodies of troops did not seem to have moved more than 300 yards from the road. A speed of movement was achieved which would have been impossible if an attempt was made to secure the flanks. Enemy troops talked a good deal during the approach march, but were careful about lights. Absolute silence was maintained just before the attack and while assembling.

e. Night attacks

During the assembly for the attack, Japanese troops tended to bunch up. Once the attack began, they made all the noise possible by firing mortars, grenades, and fire crackers, and by calling and whistling. This noise was made not only to draw our fire but also in an attempt to demoralize our troops and to encourage their own.

Night attacks were made on a small frontage, but mortars were fired well forward to the flanks to give an impression of a large force advancing on a wide front. The rear elements seemed to be more widely deployed for a probable flank envelopment.

When our troops opened fire, the Japanese tried to infiltrate through our flanks and rear. When in position, they attempted to rush our posts under cover of mortar fire and grenades.

f. Night Withdrawals

These night attacks were suddenly broken off before daylight. The Japanese withdrew again in chattering groups along the road. In two instances, the signal to withdraw was a bugle call. Snipers and observers in trees close to our main line of resistance and along trails were left behind as they withdrew. A great deal of equipment was abandoned, but no wounded were left.

g. Sniping and Field Craft

The Japanese used tree snipers to harass our troops during the day and interfere with the advance. Before opening fire the snipers would allow our troops to approach within a few yards, or to go past. These snipers cooperated with others hidden on the ground. When our troops exposed themselves to shoot at tree snipers, they drew fire from the ground. Other snipers lay hidden among their own dead and allowed our patrols and burial parties to go past before firing. The snipers' marksmanship was not as good as their fieldcraft.

The fieldcraft of these snipers was very good. They used foliage and body camouflage nets and secured themselves in the leafy tops of coconut palms and other trees. Their greenish uniform blended well with the vegetation. They were so well hidden that it was necessary to draw their fire in order to discover their position. Even then they were difficult to dislodge.

h. Defense

Japanese tactics in this action were mainly centered on attack. All defense positions were covered by a screen of snipers who were hard to deal with.

i. Infantry Cooperation with Tanks

At least two light tanks were used by the Japanese in this operation. Some machine gunners rode on the tanks or followed close behind. The glare of the headlamps prevented our troops from seeing these troops. In defiles, other infantry parties preceded the tanks to deal with antitank guns lying in ambush.

j. Deception

In addition to skillful fieldcraft, the Japanese made free use of English phrases in ruses to draw fire. Some were well chosen to give the impression that bodies of our troops were approaching the position; examples were "Do not fire, troops coming in," etc. However, a few of these expressions were quite inappropriate--as "Good morning" in the middle of the night, etc.

k. Recommendations by Brigade** Commanders

(1) Communications

Jungle fighting presents great difficulties for signal communication. Visual signaling is often impossible. To counteract this situation, it was recommended that a large and immediate reserve of wire and spare telephones be made available for issue to battalions in this type of operation. In all cases where lines and telephones were available, signal communication was maintained in the heaviest undergrowth.

(2) Transport

Only vehicles with high clearance and 4-wheel drives are recommended for this type of operation; also, that each company (if possible each platoon) be equipped with a light 2-wheel cart similar to the type captured from the Japanese. These carts are invaluable for rapid transport of mortar bombs, supplies, and ammunition, and in some cases for the evacuation of the wounded.

(3) Clothing

Recommendation was made that all enlisted men be issued capes equipped with cross-straps in place of the present type, which is a sort of cape thrown over the shoulders with a series of buttons down the front. It is awkward to handle, especially if the soldier is called upon to use his rifle.

(4) Ordnance

In place of drum magazines for Thompson submachine guns, it was proposed that the box type magazine be carried. Bayonets should be sharpened to a cutting edge to assist in the quick clearance of undergrowth. It was recommended that Royal Australian Air Force type signal pistols and cartridges be issued, so that a more economical signal ammunition code would be established for the recognition of troops in forward areas, instead of the method involving considerable expenditure of Very cartridges. Finally, it was recommended that guns place one round of smoke on each side of the target to indicate positions to aircraft for bombing and strafing. This method was tried, and the round of smoke was placed on each side of the target according to the direction of the wind. This proved very effective, as the smoke drifted very slowly, hung about the tops of the trees, and was easily sighted by Allied planes.

*Based on British report.
**Brigade approximates U.S. infantry regiment.