As early as 1942, Australian troops advancing along the Kokoda Trail across the Owen Stanley Mountains, Papua-New Guinea, encountered suicide snipers: volunteer rearguards lashed into the treetops. Similar tactics were met with by US Marines on Tulagi and Guadalcanal in 1942. By the time of the US landings at Cape Torokina, Bougainville, in November 1943, a countermeasure had been found in the Doberman Pinschers of the 1st Marine Dog Platoon, 2nd Marine Raider Division. After several months’ training, these canine auxiliaries proved able to “point” snipers concealed in trees or bush.
Suicidal weapons and tactics also played a significant part in Japanese anti-tank measures. Most island garrisons were short of heavy artillery or shells, especially anti-tank guns – since tanks were used in comparatively small numbers in most Pacific campaigns – and often resorted to grenades and mines of improvised types that called for self-sacrifice by their users. The IJA’s Type 99 Hakobakurai grenade-mine could either be placed in advance as an anti-tank or anti-personnel trap or be thrown at an AFV, to adhere by means of four magnets set around its canvas cover. When thrown, however, it almost invariably bounced off, and many Japanese died in attempting to approach tanks closely enough to affix magnetic charges by hand.
By 1943, Japanese infantry trained as tank-hunters were often using either hollow-charge grenades effective only when thrown from c.10yds (9m), or “satchel charges”, impact-fuzed explosives in a cloth bag (naval troops sometimes used small depth charges in sacks) to be tossed on to or thrust beneath a tank. Soldiers often strapped the charges to their bodies and flung themselves beneath the tanks’ tracks. On Okinawa, the US 193rd Tank Battalion assaulting the Shuri Line at Kakazu, 19 April 1945, lost 22 of the 30 tanks committed – six of them to the suicide assault squads of the IJA’s 272nd Independent Infantry Battalion, who sacrificed themselves to place 22lb (10kg) satchel charges beneath the Shermans’ bottom plates.
On Kwajalein, in February 1944, a US tank commander reported an attack by five Japanese armed only with swords, who beat furiously on the armour plating until all were shot down. Hardly more effective were the “human bombs” encountered by British armour during the advance into Burma in 1944–45. A Japanese soldier would crouch in a well-camouflaged fox-hole in a road or track, with an artillery shell or aircraft bomb with an exposed impact-fuze in its nose. He would attempt to detonate his charge with an improvised hammer as a tank or truck passed above him.
In 1945, anti-tank units were advised by an IJA manual to attack “with spiritual vigour and steel-piercing passion”. The weapon provided was the “lunge mine”, a conical grenade mounted on a 5ft (1.5m) pole. Approaching a tank, the soldier pulled out the safety pin separating the striker at the pole’s end from the percussion cap. The pole was then wielded like a bayoneted rifle, thrust against the armour plating, where the rods projecting from the grenade’s head ensured a “stand-off” effect. As well as destroying its user, the charge was claimed to penetrate up to 4–6in (100–150mm) armour at 0º, but details of its effectiveness are scanty.
An odd “tank-busting” project of the IJNAF must be mentioned. Yokosuka planned to build, with the Mizumo company, a suicide weapon based on the small, experimental MXY5 assault glider of 1941–42. This unpowered aircraft would either make a rocket-assisted takeoff or, for longer-range missions, be towed aloft by a “Frances” bomber. Its pilot was expected to deliver an internally-mounted, impact-fuzed charge of c.220lb (100kg) with pin-point accuracy in a steep dive on an enemy AFV. Only one prototype of this Shinryu (“Divine Dragon”) glider-bomb was completed.