Although the Allied armies have had relatively little experience with Japanese tank units in the current war, there is considerable evidence that the Japanese will use large armored units when the terrain permits their effective operation. It may be expected, also, that lessons learned from the European and North African war theaters will exercise an influence on their armored tactics.

In combat with Allied forces the Japanese have utilized light and medium tanks, as well as tankettes, in support of infantry in direct frontal attacks. After the infantry reached their objective the tanks were withdrawn without attempting to exploit the limited gains. In Malaya tanks were brought up wherever the infantry was unable to advance. The tanks normally attempted to force a passage for the infantry by a frontal assault. If this failed, the tanks were sent against the hostile flanks. On occasion, however, Japanese tanks have attacked by moving directly down roads with the infantry following in trucks. Unless effective road blocks were prepared by Allied forces, the tanks struck at artillery and other installations as much as 8 to 10 miles in the rear of the main Allied positions. When a road block was encountered, fire from the tanks was used to get around the flanks by infiltration tactics. Only a very few operations have involved Allied tanks directly against Japanese armored vehicles.

Large Armored Formations

No large commitments of Japanese tanks have occurred thus far outside the Chinese theater. Tactical studies in a Japanese army tank school, however, give precise instructions for the employment of large armored formations. For an attack on a lightly held enemy position, Japanese doctrine maintains that a minimum of 30 to 40 tanks are required. If the enemy is in a strongly defended position, it is stated that at least 60 will be needed, and this number will be increased to 100 in the event hostile artillery shelling and aerial bombing are unusually heavy. The number of tanks assigned to regiments in some cases, at least, has been increased, with 15 being allocated to a platoon instead of ten as formerly was the practice. Yet tanks would seem to be an ideal weapon for the Japanese in the envelopment maneuvers that are so favored in their tactical doctrine and practice. Where the terrain is favorable it can be anticipated that they will utilize tanks in wide encircling movements to cut hostile lines of communications and strike at vital rear areas.

Japanese tactical doctrine stresses the utilization of tanks in what is termed a "mobile mass." In operations in which they are committed in such a fashion tanks constitute the main fire element in what is essentially an attempt to attain a decisive victory in one stroke. The Japanese believe that such tank tactics can be resorted to only in suitable terrain and that the nature of the terrain really is the chief limitation upon the employment of large tank formations. In any event, tanks are committed as a "mobile mass" only at "a momentous time and place when a decision of the entire army is in balance." If these conditions prevail, Japanese doctrine maintains that the loss of even the entire combat power of the tanks will be justified in view of the magnitude of the results achieved.

Inherent weaknesses and disadvantages of tanks are recognized by the Japanese. Yet the great advantages of tanks—high mobility, great offensive and fire power, as well as the power to crush and penetrate—cannot be found to a comparable degree in other weapons, and the Japanese recognize that the tank will be used to an increasing extent by modern armies.

It follows, according to Japanese reasoning, that when the objective is to secure a decision by armored operations alone tanks should not be committed in a piecemeal fashion and should never be used in a struggle of attrition. At best, tanks require extensive maintenance facilities; damage and loss in combat normally will be severe, and replacement both of equipment and personnel is difficult.

Ideally, tanks employed in "mobile mass" should be directed against weak spots in the enemy's lines, according to Japanese doctrine. With the constantly increasing efficiency of antitank guns, which threatens to overbalance compensating improvements in tank armor, the element of surprise becomes progressively more important. A Japanese tactical treatise says that "the essence of tank warfare is to take the enemy by surprise and assault him suddenly with concentrated power." Antitank weapons, however, are considered intrinsically defensive; the Japanese believe tanks are the only ground weapon truly capable of effectively opposing tanks. The airplane is becoming the tank's greatest enemy, according to the Japanese, necessitating important changes in the design of armored vehicles. Opportunities for plane-tank cooperation, however, are most promising, and Japanese tactical writings speak almost ecstatically of the prospect of gaining crushing victories with huge tank forces operating under the coverage of swarms of planes.

Despite Japanese appreciation of the potentialities of mass employment of tanks, the infantry support role doubtless will continue to be emphasized, affecting not only tank tactics but also the design of tank matériel. Although Japanese tanks do not compare unfavorably with armored vehicles used by the Allies in their speed-weight ratios, they lose speed more appreciably on cross-country runs. Japanese tanks are bulkier in proportion to their weight than comparable Allied vehicles because of their smaller armor basis. This feature is a direct resultant of the fact that, tactically, the Japanese relied primarily upon their infantry to neutralize hostile antitank weapons. Now, however, when Japanese tanks are attached to infantry, one of their missions is the elimination of antitank weapons not neutralized by artillery fire.

Another connection between equipment and tactics can be seen in the allocation of radio sets. Only one set is issued to each tank platoon, and this factor inevitably entails constriction of the area of maneuver of tank units. If a platoon leader's tank is knocked out in combat, the entire platoon is deprived of all except visual communication with higher echelon command.

Japanese reliance upon infantry explains the existence of a large number of independent tank units in the Japanese army which readily can be attached to infantry commands. This factor also explains the failure to coordinate the artillery with tank units more effectively, for artillery, too, frequently is put under infantry control.

Two Methods of Cooperation

Japanese tactical doctrine distinguishes between two methods of tank cooperation with infantry. One method requires the tank commander to designate the infantry forces with which the tanks are to cooperate in response to such requests for support as are received from the infantry commanders concerned. The other method is predicated upon advance specification of the objectives which the tanks will attack. If the former plan is utilized—that is, if the tanks are directly allotted to infantry units—the tank regiment commander gives the general outline of the plan and leaves the details of its execution to the tank company commanders. If, for example, it is necessary for the tanks to execute a reversal of movement to facilitate the forward advance of the infantry, the movement is made upon the order of the tank company commanders, often in response to a direct request from the infantry for such a maneuver.

On the other hand, if the tanks are assigned particular objectives, the tank regiment commander retains direct control throughout the entire course of the action, and the tanks are committed as a unit. This method of tank-infantry cooperation is favored if time is short and it is difficult to foresee changes in the tactical situation that may develop during the engagement. It also should be noted that in this form of tank-infantry coordination the tanks may be committed by platoons; if they are assigned to infantry units, however, nothing less than a tank company will be committed.

It also must be decided whether the tanks will be used in coordination with infantry primarily for purposes of exploitation, or for the utilization of their momentum to facilitate infantry penetration of the enemy line. In exploitation operations the Japanese tanks will be so deployed and committed that they can seize tactically important areas, confuse hostile deployments for attack, and strike at enemy artillery or other vital rear installations. If the tanks are utilized to give impetus and momentum to the infantry assault, they will advance in close coordination with the infantry. It is always possible, according to Japanese doctrine, to employ both methods simultaneously, particularly if tanks are available in ample numbers. While some can be used for direct support missions, the remainder can be held in reserve for exploitation of such successes as may be achieved by the assault.

Leading tanks also occasionally are used in offensive operations. If more tanks are available than it is estimated are necessary for close infantry support, some may be committed as leading tanks, usually under division control.

A number of fundamental principles are emphasized in Japanese infantry-tank attacks. Close liaison is maintained at all times, with frequent rallying of the tanks if necessary to ensure maximum coordination of offensive effort. If the infantry assault does not progress as planned, the tanks will concentrate on the enemy obstacles or strongpoints which constitute the most effective impediments to the forward movement of the infantry. Especially prompt and vigorous action is taken against enemy positions from which flanking fire is being delivered against the Japanese infantry.

If Japanese tanks encounter an antitank installation within the enemy positions, an immediate decision must be made whether to detour around it or make a frontal thrust to liquidate it. Incipient enemy counterattacks, according to Japanese doctrine, are frustrated by striking at the counterattack base, the infantry deployed for the counterattack, or the hostile tanks which may be spearheading the maneuver, depending upon the immediate circumstances.

Rallying points are designated for assembly of the tanks after their mission is accomplished and preparation for the next attack phase is necessary. The tanks also assemble at rallying points when the assault is suspended at night or because of the tenacity of enemy resistance. Restoration of combat strength is the main objective of rallying; sites are chosen to afford maximum efficiency in the regrouping, replacement, and repair of the combat vehicles. Special care is taken to collect all damaged vehicles and to initiate repair where feasible.

Coordination Stressed

When artillery and tanks cooperate with the infantry, both support weapons must be carefully coordinated, state Japanese tactical instructions. When the infantry attacks immediately after artillery preparatory fire, the tanks should have a line of departure and a jump-off time that will not interfere with the consummation of the artillery plan or the full realization of its potentialities by the infantry. The danger of friendly artillery fire will be disregarded, however, if it becomes necessary for Japanese tanks to overwhelm defense capabilities on the enemy's flanks which unexpectedly may be revealed. Where there is no artillery preparation, the tanks ordinarily initiate their attack immediately upon the completion of the preparatory phase of the infantry attack.

Tank attacks, or infantry attacks supported by tanks, sometimes are facilitated by the assignment of special engineer parties to cooperate with armored vehicles. Personnel of these engineer parties are especially trained in the techniques of demolishing tank traps and other obstacles which could hinder the advance either of the tanks or of tank-supported infantry.

In one observed instance an engineer party consisted of a leader and five men, equipped with 122 pounds of explosives, a smoke discharger, picks, shovels, and other tools. Both personnel and equipment were carried on the outside of two tanks. These tanks stopped about 10 yards from an obstacle to permit the men to dismount and unload their equipment. As soon as this was accomplished, the tanks retired to a position about 50 yards to the rear, and with tank-gun and machine-gun fire covered the engineer party which in the meantime had begun its demolitions. By this technique the Japanese expect obstacles to be destroyed promptly.

Orders and Objectives

The Japanese Army lays stress upon precise orders and clearly specified objectives in actions involving tank-infantry cooperation. If tanks are attached to an infantry battalion, they will be under the battalion commander's control. Company commanders, nevertheless, are expected to maintain liaison with the tank commander to facilitate effective cooperation and to expedite prompt exploitation by the infantry of such successes as the tanks may achieve.

The infantry battalion commander's orders to the tank unit under his control include a statement of his plan as a whole. Tank objectives are specified clearly, and the obstacles which they are expected to remove likewise are designated. Assembly areas, line of departure, and H-hour are stipulated, and the methods the tanks will use in crossing the line of their infantry also are prescribed.

To enable the battalion commander to assign objectives as precisely as possible, company commanders are expected to inform him about the nature and location of primary tank objectives in front of their sectors, such as antitank guns, natural and artificial obstacles, enemy heavy weapons, etc.

If there are no primary tank objectives that demand immediate attention, or their location cannot be ascertained, the tanks may be sent against the enemy flanks. When Japanese tanks are used in an attack on hostile flanks, the battalion commander sends infantry with them in a coordinated assault. The infantry also are assigned the task of mopping up pockets of enemy resistance that survive the initial attack. These infantry units assigned to cooperate with the tanks ordinarily are drawn from the forward companies opposite the flank or flanks against which the assault is made.

In attacks on hostile flanks, Japanese doctrine directs the infantry battalion commander to concentrate the firepower under his command against enemy antitank weapons. If necessary, details are sent forward to clear a passage for the tanks through areas where the enemy has antitank weapons emplaced or can be expected to have them. Japanese doctrine emphasizes the principle that infantry should cover the tanks and protect them against antitank fire. Yet their orders on Guadalcanal directed just the opposite procedure. There the tanks were sent against hostile antitank weapons, and every vehicle was destroyed.

Regimental Tactics

Details of Japanese tank tactics are available in several tactical treatises. The tank regiment when advancing, according to Japanese doctrine, will have a frontage of 500 to 550 yards. A patrol of tankettes is sent ahead for reconnaissance purposes, followed by "a direct guard", consisting of a light tank platoon utilized to develop enemy positions preparatory to the assault. Regimental headquarters follows the "direct guard" (advance guard), and after it comes a forward platoon of light or medium tanks to deal with enemy antitank weapons that may open fire. The main body then follows with the remainder of the company which furnishes the direct guard and forward platoons, flanked on each side by a tank company. The fourth company of a four-company regiment brings up the rear.

A medium tank company on the march will form a column 915 yards long; a light tank company, one of 525 yards. The platoons are drawn up in diamond formation, and the company forms a diamond of diamonds. In deploying for battle three platoons ordinarily will draw up abreast, with the fourth just to the rear of the center of the line. In special cases, however, all platoons may be deployed abreast.

If the depth of the enemy position is estimated to be approximately 1,425 yards, the Japanese assume that the position will be defended by at least 2 or 3 antitank guns, 6 heavy machine guns, 5 mortars, and 9 to 12 light machine guns. The front of a Japanese regiment in an attack on such a position will be 550 to 875 yards, and a tank company will be assigned to the support of each infantry battalion.

The attack is made by the tanks in three echelons. The first echelon is under the direct control of the tank regiment commander. Its objective is to establish a passage for the advancing infantry. The tanks of this echelon deal with enemy antitank guns and strong fire points that have not been destroyed by preparatory artillery fire. Those that are not liquidated by the initial attack subsequently are mopped-up by the infantry. It should be noted that this procedure is somewhat different than would be the case if a smaller number of tanks were involved. In a small-scale employment of tanks to support infantry, Japanese doctrine assigns the liquidation of enemy antitank weapons to the infantry, rather than to the first tank echelon as is the practice in an attack by a regiment or more of tanks.

The second tank echelon is under the control of the battalion commander in charge of the infantry assault wave. Tanks in this group lead and support the attacking infantry, pinning down or liquidating the enemy's automatic-weapon personnel. The third tank echelon remains in reserve under regimental control. The reserves are held to exploit successes that may be won by the first two echelons. If a break-through is made by the advance tanks and the infantry, the reserve tanks will proceed through it to strike as deeply as possible into the enemy's rear areas.

Division-Strength Attack

In an attack of division strength, Japanese doctrine states that the front will be about 2,735 yards. Three tank regiments with a total of 135 tanks are employed, with 45 to a regiment, 15 to a company, and 5 to a platoon. As in the case of an attack on a smaller scale, the armored vehicles are committed in three echelons. Two infantry regiments are deployed in the front line, and one tank company is placed considerably in advance of each of them. The primary mission of this first tank echelon is to neutralize enemy antitank weapons and strongpoints not previously destroyed by artillery fire and to clear a path for the second echelon, which comprises the major infantry assault units in addition to the tanks assigned to this echelon.

The second tank echelon is deployed immediately in front of the infantry, with one company in front of each of the four battalions. It moves 400 to 500 yards behind the first echelon, and its mission is to cover and support the infantry assault with special attention to the liquidation of enemy automatic weapons. If the situation warrants, the second echelon may "leap-frog" through the first. A regiment of tanks is held in reserve as the third echelon under direct control of the division commander, primarily for exploitation of such success that the assault may achieve. It also may be used to reinforce any area requiring such aid, perhaps by attachment to an infantry unit.

When the support of the infantry by the tanks must be exceptionally close there are some important modifications in Japanese armored tactics. The tanks are allocated to two combat units. The first combat unit is divided into left and right formations, each of which is preceded by a patrol of light tanks utilized to develop the enemy position and draw the fire of his antitank weapons.

Both the right and left formations of the first combat unit consist of four platoons, drawn up in two columns, each of two platoons. The two front platoons advance with the infantry; the two rear platoons are used to swing around the flanks of the two leading platoons to engage enemy antitank weapons, as soon as the location of them is ascertained. A platoon of engineers follows the first combat unit. The second combat unit consists of two tank platoons, assigned the mission of liquidating the enemy's automatic weapons which survive the first echelon assault, and a reserve. The reserve may be used to provide necessary reinforcements or to exploit success.

A dawn attack is really a night maneuver for Japanese tanks, which normally will proceed to their line of departure under cover of darkness guided by noncommissioned officers especially trained in tank tactics. Thorough preparation is made, with major emphasis upon the removal of natural or artificial obstacles to the advance of the tanks, or the provision of facilities for their evasion. Arrangements are completed well in advance for the exact procedure to be followed when the Japanese tanks "leap-frog" the infantry line preparatory to spearheading the attack.

Preparation for a night attack, according to Japanese principles, is even more elaborate and inclusive than it is for dawn attacks. As many as a platoon of tanks may be assigned to one infantry company for night attacks. Tank objectives will include the heavy weapons of the enemy's first line of defense, obstacles, and flank defenses. The objectives preferably are designated so as to permit the tanks to move to their departure line by daylight, unless enemy observation facilities make this inexpedient.

The Japanese feel that pursuit affords the best opportunity to exploit the advantages of tanks to the full. It is considered necessary to arrange maintenance and supply facilities carefully so that continuity of pursuit may be facilitated. Clear objectives should be selected, and Japanese tank units are directed to proceed against these as directly as possible regardless of losses. Pursuit should be unremitting and audacious, even if only one tank survives to complete the mission.

Tank operations, according to Japanese tactical principles, are not conducted with the purpose of precipitating tank-versus-tank engagements. Nevertheless, in operations against a modern, well-equipped army such battles are regarded as inevitable, for, according to the Japanese view, the tank in the last analysis is the only ground weapon capable of successfully opposing tanks. Consequently, Japanese tank commanders are directed to be in constant readiness to engage in battle with enemy armored vehicles.

Strive for Initiative

The most important necessity for success in tank-versus-tank engagements is the constant retention of the initiative, the Japanese believe. Alert foresight, quick commands, firm determination, and cohesive organization are the factors that allegedly will enable the Japanese tank commander to retain the initiative and thus gain a decisive victory. Japanese tank units are expected to proceed on the assumption that they enjoy superiority in a situation where quick decisions are necessary and are directed to launch immediate attacks against the flanks and rear of the enemy's tank formation. Japanese armored units will fight in closely integrated and controlled maneuvers, attempting to destroy enemy vehicles in detail. The fire of the Japanese tanks, according to prevailing doctrine, will be concentrated upon enemy command and leading tanks.

"Long-Range Raids"

Considerable attention also is given in Japanese tank doctrines to what are termed "long-range raids" which may lead to meeting engagements. On a "long-range raid" the advance of the tank regiment is conducted on a front from 325 to 550 yards wide. A reconnaissance unit constitutes an advance force and is assigned the mission of securing all available information in regard to terrain, routes of advance, enemy forces and their dispositions, and all other intelligence that may be of use to the commander of the advancing tank regiment. A "direct guard" (advance guard) consisting of one tank platoon follows the reconnaissance unit. This unit drives in light enemy units that may be encountered or develops resistance which subsequently can be dealt with by the main body.

Regimental headquarters follows the "direct guard", and behind this group a tank company advances on a front of from 55 to 110 yards. The field artillery attached to the tank regiment and the engineers unit follow in parallel columns behind the first tank company. A tank company is on each flank, abreast of the artillery and engineers columns. These companies, in the event of a meeting engagement, can sweep out against the enemy flanks in an envelopment maneuver, or they may aid the leading tank company in the speedy destruction of enemy obstacles and antitank weapons. The artillery provides direct fire support, while the engineers move ahead to aid in the elimination of obstacles.

Behind the line formed by the tank companies, the artillery, and the engineers come the infantry, usually motorized units that can deploy quickly for either frontal assault or a holding frontal action and an envelopment maneuver.

A second echelon of tanks follows the infantry. It is used as a reserve, committed as the tactical situation warrants after the battle is begun. As in other types of attacks, the reserve tanks can be used for exploitation of penetrations of the enemy lines or to reinforce tank units that may require aid in the accomplishment of their missions.

In contrast to the "long-range raids" involving at least a tank regiment, similar Japanese tank units are employed on what are termed "raids". These are undertaken, often upon the request of infantry commanders, to capture terrain features of tactical importance, to confuse the enemy, or to deliver surprise attacks on enemy artillery, headquarters, and other important installations. Heavy losses of tanks are anticipated on raids of this nature which therefore should only be undertaken when the potential results can justify the losses that may be incurred.

The front of the advance on such operations is from 650 to 765 yards, and the depth of the formation ordinarily will be from 440 to 660 yards. The tanks are allocated to two "combat units". The first combat unit, according to Japanese tank-training literature, is assigned the mission of liquidating enemy antitank weapons, whereas the primary objective of the second combat unit is the destruction or neutralization of hostile automatic weapons.

Emphasis on Offense

Japanese tactical doctrine emphasizes the offensive almost exclusively. The defense is considered to be merely a passing phase in combat during which the Japanese must assume the ignominious role of defense because of the overwhelming superiority of the enemy. The object of defense is believed to be the depletion of the enemy's strength until such time as the Japanese can initiate a counterattack.

Since the tank is predominantly an offensive weapon, this factor, taken in conjunction with the general Japanese views on defensive tactics, means that practically no attention is paid to defensive tank tactics. In a defensive situation the tanks are to be employed for counterattack purposes. They are expected to deliver short, speedy assaults upon the designated objectives in close cooperation with artillery. As soon as their mission is accomplished, according to Japanese doctrine, they will break off the engagement. If enemy tanks are present in superior numbers, counterattacking Japanese tanks try to coordinate their action with their antitank-weapons fire. In recent action the Japanese have dug in their tanks and used them defensively as artillery or even as antitank weapons.