In late 1944, the Allied forces were
advancing towards the Japanese home islands. While Germany was months away
from surrender, in the Pacific Theatre, American troops were closing in on Japan,
taking the Japanese islands one by one. The Japanese had lost several major battles,
hundreds of men and aircraft, and they were struggling to compete with the Allied industrial
capacity. And yet despite their heavy losses, they were unwilling to surrender.
A radical strategy emerged. Kamikaze. In the later stages of the Second World War in the
Pacific, Japan was faced by overwhelming American naval power. Increasingly unable to make effective
air attacks against American ships, Japanese forces turned to suicide attacks, using pilots
flying aircraft laden with bombs as improvised missiles, in the hope of destroying Allied ships
at the cost of the aircraft and the pilot’s life. The suicide attackers were known as the kamikaze. Their name comes from two Japanese words,
‘kami’, meaning god, deity, or divinity, and usually referred to the old gods
of Japan’s traditional Shinto religion. ‘Kaze’ meanwhile means wind or air, and so
kamikaze is usually translated as ‘divine wind’. The term was first used in connection
with the attempted Mongol invasions of Japan in the late 13th century, when Mongol
fleets were destroyed by typhoons. In 1944, a Special Attack Force was formed,
a group of official kamikaze pilots. The kamikaze’s significant action took place during
the Battle of Leyte Gulf in October 1944. The kamikaze’s first significant action
was during the Battle of Leyte Gulf, which took place at sea around the Philippines
in October 1944. At Leyte Gulf, the Japanese attempted to prevent Allied forces
from occupying the Philippines, precipitating one of the largest
naval battles in history. During the battle, five kamikaze A6M Zeros
attacked several escort carriers. All five missed their targets or were destroyed by anti-aircraft
fire. However, as one aircraft aborted, they aimed instead for USS St Lo, diving into the
flight deck and sinking the carrier. It was the first major battleship sunk by a kamikaze attack.
The following day, dozens more kamikaze strikes were made. In total, five ships were sunk and
23 were heavily damaged by the kamikaze attacks. After the Battle of Leyte Gulf, the Japanese
decided to expand their kamikaze strategy. But before we look at that, a quick
word of thanks for our sponsor, World of Warships. This is strategy-based game
where players immerse themselves in naval battles. The ships are designed from historical blueprints,
and there are dozens of geographies to choose from – including the Pacific Theatre in WW2, and
Japan’s last naval stand against the Allies. Most of the aircraft used for kamikaze strikes
are standard Japanese combat aircraft. Foremost among them is the Mitsubishi Zero fighter.
This aircraft had given the Japanese navy control of the skies through 1941 and 1942, but by the
start of the kamikaze campaign in 1944 the Zero is outclassed by more powerful American fighters.
This particular aircraft was operated in the Pacific and was abandoned on the island of Taroa
when it became unmaintainable. It was recovered, as a wreck, in the 1990s and later passed
into the Imperial War Museum’s collection. During the kamikaze campaign, around
650 Zero fighters are expended, more than any other type, but the campaign
sees the use of a wide variety of aircraft, even including wooden biplane trainer planes. Alongside the use of Zeros and other aircraft in
the Kamikaze campaign, the Japanese also began to develop an aircraft specifically designed for
suicide missions – the Yokosuka MXY-7 Ohka. Work begins on the design of the Ōka in 1943,
actually before the first kamikaze attacks are made. The idea comes from a Japanese transport
pilot named Mitsuo Ōta. Initially his designs go nowhere, but in 1944 he’s summoned to
present his design to the Japanese Navy. From June 1944, following heavy Japanese aircraft
losses in battle around the Mariana Islands, development transfers to the Japanese naval
arsenal at Yokosuka. Test flights begin in October 1944, with a successful test flight
of a rocket-powered Ōka in November 1944. The IWM’s Ohka is a model 11 –
the only operational variant. The Ohka is rocket-powered glider carrying
a large, 1,200-kilo explosive warhead. It’s about 6 metres long and 5 metres wide.
With its rockets lit it could reach 400mph, and in its final dive its speed
might reach as much as 575mph. The Ohka’s rockets had limited range, and so
it had to be carried into action by a larger aircraft, typically a twin-engine Mitsubishi G4M
bomber. Once the bomber reached the target area, the Ohka pilot would detach himself
from the bomber, ignite his rockets, and aim for an enemy vessel.
Annie: Once the rockets were ignited, the pilot would
fly the missile towards the target. The Oka could reach incredible speeds, making it difficult
to counter the attack, but also difficult for the Ohka pilot to control. Updated versions of the
Ohka were in development aiming to fix some of the aircraft’s flaws, but these were not developed
in time, and only the Ohka-11 saw active service. The Allied troops who encountered these
attacks referred the aircraft as Baka Bombs, a Japanese word meaning foolish. The idea of
a suicide aircraft was an alien concept in the West. But for the Japanese, their culture
had long understood suicide as something that, under certain circumstances, was honourable and
appropriate behaviour. A samurai might commit suicide in order to avoid the shame of defeat.
The kamikaze didn’t necessarily think of their mission as one of suicide. Instead, they saw it
as fulfilment of their duty to their Emperor, a ruler widely believed to be divine.
The word Oka in Japanese means Cherry Blossom. The cherry blossom is a popular symbol in Japanese
culture. Cherry blossom is beautiful, but its beauty is short-lived, and soon the petals fall
from the trees, or are blown away by the wind. For the Japanese, the cherry blossom has become
a symbol for the fleeting nature of human life. What did you think of the kamikaze? The whole tactic…? Bloody idiots. For the
hundreds they sent out, there were only a few that succeeded. Certainly did a hell of a
lot of damage, which you didn’t have much defence against. But the majority of them just crashed
into the sea and that was it. They didn’t get shot down, or they ran out of petrol, or they missed
their targets. Because they weren’t very well trained. They were only taught to fly a plane from
here to there and that’s all they knew. And we had so many guns on the ship. Incredible. Not
only 4mm or 5mm, but Oerlikon, pompoms and all sorts of things. But if you’ve got
that kamikaze determined to get through, that’s it, nothing’s going to stop him, doesn’t
matter how much aircraft fire you’ve got. The Japanese ramped up their kamikaze campaign,
but the Allied naval forces had learnt lessons during the battle of Leyte Gulf and had
begun to prepare for the threat of kamikaze. The Allies had a number of defences against
the kamikaze. Away from the ships themselves, the key defence was combat air patrol by naval
aircraft, trying to intercept incoming Japanese aircraft before they reached Allied ships.
Naval aircraft were also used to attempt to suppress Japanese airfields, attacking
kamikaze as they took off, bombing runways, and attacking aircraft on the ground.
The Allies also used destroyers as radar pickets; these were small warships fitted with radar.
Positioned twenty miles out from the main fleet, these ships provided early warning of incoming
air raids. Unfortunately for their crews, these ships were very exposed, and were often
subjected to attacks by multiple kamikaze. Aboard ship, the key defence was
provided by anti-aircraft guns. A large fleet aircraft carrier like the
USS Bunker Hill would carry a dozen 5-inch anti-aircraft guns, as well as dozens of
smaller 40mm and 20mm guns. New technology, such as proximity fuzes and radar gun-laying,
made anti-aircraft fire more effective. Finally, there was damage control. By 1944 the
Allied navies had sophisticated and well-trained damage control procedures. It was rare for
a kamikaze strike to sink a vessel outright, and so a critical factor in a vessel’s
survival was the efficiency with which a ship’s crew could extinguish fires,
repair structural damage, and restore a ship’s systems. These measures reduced the loss
of ships, especially to fire, and also reduced the amount of time that damaged ships would need
to spend under repair at bases or dockyards. In October 1944, a special attack Squadron was
formed specifically to fly the Oka into battle, the Japanese 721st Naval Air Squadron, known as the Jinrai Butai, which translates as
Divine Thunderbolt Corps, or the Thunder Gods. I think inevitably different pilots had
different feelings. Kamikaze pilots are typically thought of as being fanatical zealots,
eager to die for their country and their Emperor. It’s likely that some really did feel that
way. Others will have had more mixed feelings, and acted more out of a sense of obligation
than enthusiasm. And not all kamikaze pilots were volunteers; after the volunteers ran out
others were shamed or coerced into ‘volunteering’. By late 1944, soon after the first successful
test flight an Ohka, the US forces were in reach of the home islands. The Ohka went into
production, as the Japanese prepared for battle. By the spring of 1945, the Japanese strategic
situation is dire. In summer 1944 US forces captured the Marshall and Palau islands. By
November, islands like Tinian, Saipan and Guam, are bases for US heavy bombers able to strike
at the Japanese home islands. This leads to devastating air raids, including against Tokyo
in March, which may have killed 100,000 people. At sea, US submarines were sinking Japanese
merchant shipping, hampering the import of vital raw materials. On land, Japanese manpower
is being consumed in battles in China, in Burma, as well as in New Guinea and the south Pacific.
For the Japanese, Okinawa isn’t just another Pacific island, it’s actually part of Japan
proper, so the looming battle of Okinawa has political and psychological significance too.
The initial invasion of Okinawa took place on 1 April 1945 - the largest amphibious
assault in the Pacific Theatre. It became the bloodiest of the battles in the
Pacific, particularly for the Japanese. For the invasion of Okinawa, the Allies assemble
a massive invasion fleet. Dozens of aircraft carriers, 18 battleships, two dozen cruisers
and well over a hundred destroyers and destroyer escorts. The Allied invasion fleet has enormous
firepower, in both naval guns and aircraft. At first American troops make rapid progress,
because the Japanese choose not to resist the initial landings. Instead the Japanese
build immensely strong defensive positions, particularly in Okinawa’s mountainsides. These
defences prove enormously costly to overcome. In addition, tens of thousands of Okinawan
civilians were killed, having suffered terribly. At the Battle of Okinawa, Kamikaze
became a core part of the Japanese naval defence strategy. And it was here
that the Ohka were brought into combat. Around 850 Ohka were built in total,
but relatively few saw combat. In March 1945, the Ohka flew their first
combat sortie, but it had resulted in failure. One of Ohka’s biggest weaknesses was its limited
range, and its need to be carried into battle by a larger bomber plane. Its parent aircraft
was vulnerable to interception. In their first combat sortie, the Japanese attacked
with 16 bombers carrying Ohka, escorted by 30 Zero fighters. They were intercepted by
two squadrons of US naval fighters, with the loss of every single bomber and their Ohka.
On the 1 April 1945, the first day of the invasion of Okinawa, six G4Ms carried Ohkas into battle.
It’s uncertain whether any of the Ohkas hit their targets, but the USS West Virginia was damaged.
None of the G4Ms returned. Just over a week later, nine G4Ms and Ohkas went into battle again.
This time, a destroyer was hit and sunk – the USS Mannert L. Abele. Over April, May and
June, numerous attacks were launched by the Ohkas and G4MS against the US fleet off Okinawa,
alongside hundreds of other kamikaze attacks. Many of the G4Ms were destroyed, and many
Ohkas failed to hit their targets, likely falling victim to anti-aircraft fire.
Alongside the Ohka, the Japanese continued to fly Kamikaze missions with Zero fighters and a
variety of other aircraft and even suicide boats. Between April and June the Japanese flew
over 400 kamikaze sorties at Okinawa. The British Pacific Fleet also came under
fire from kamikaze attacks in the battle. Significant damage was done to the Task Force,
but nothing debilitating. The armoured flight decks of the British carriers meant they faired
better under these bombardments than the US carriers’ with flight decks made of wood.
Ultimately, Kamikaze missions played a significant role in the Battle of Okinawa, but it
was not enough to turn the tide for the Japanese. Around 350 vessels were hit by kamikaze.
47 were sunk and the rest damaged. Of the ships sunk, none were strategically
important, and all could be replaced. Among the damaged ships were thirty-one aircraft
carriers of different types. In some cases, for instance to Bunker Hill, the damage was severe
enough to put the ship out of action for months. But the kamikaze could never inflict enough
damage to derail Allied naval operations. Nonetheless, their human toll was appalling.
The Japanese expended 2600 aircraft in kamikaze attacks, and with them the lives of 4000
airmen. The attacks killed more than 7000 Allied naval personnel, and wounded many more.
The kamikaze failed for a variety of reasons. I think a big one is faulty assumptions.
The Japanese overestimated how many kamikaze would be able to evade Allied
fighters and anti-aircraft guns. They overestimated the likelihood
of direct hits against enemy ships, and overestimated how much damage a crashing
aircraft could do to a large warship. The Japanese also overestimated how much impact the kamikaze
would have on Allied strategic decision-making; they thought the psychological effect of their
attacks would be so demoralising that it would reduce the Americans’ will to fight the
war to the bitter end. They were wrong.
