The Battle of Okinawa. Americans know it as the “typhoon of steel.” The Japanese called it tetsu no ame, “the
rain of steel.” The battle was the bloodiest in the Pacific
Theater during the Second World War, costing the United States more than forty-nine thousand
casualties, including U.S. Ground Forces Commander, Lieutenant General Simon Bolivar Buckner Jr. The Japanese losses were even greater, with
over one hundred ten thousand killed. Local Okinawans suffered the greatest with
an estimated one hundred fifty thousand killed. Between 1 April and 22 June 1945, American
Sailors, Soldiers, Marines, and Airmen battled against determined Japanese troops in subterranean
networks, kamikazes from the air, and suicide naval attacks, in what can be considered a
pre-cursor to the concept of multi-domain operations, or MDO. American planners predicted that the Japanese
would fight fiercely for Okinawa—and indeed they did. The Japanese forces needed to hold Okinawa
long enough for Japan to mobilize its defense of the mainland. The Americans needed to seize Okinawa in preparation
for the planned assault on Japan. The Americans would succeed, but only after
weeks of fighting the costliest battle of the Pacific War. The ultimate goal of U.S. strategy in the
Pacific was the unconditional surrender of the Japanese Empire. In May 1943, the Allied Combined Chiefs of
Staff approved the “Strategic Plan for the Defeat of Japan.” In this plan, the U.S. Joint Chiefs of Staff
outlined the need to “maintain and extend unremitting pressure against Japan,” with
a major goal being “an overwhelming air offensive.” The U.S. dual drive through the Central and
South West Pacific areas were aimed at controlling the South China Sea and securing air bases
in China. But after establishing air bases in the Marianas,
General MacArthur’s announcement that he could capture
Luzon two months earlier than expected, and dire estimates of the forces needed to secure
Formosa, all nullified the desire to capture areas on the Chinese coastline. This ultimately freed up the U.S. Central
Pacific Forces to concentrate their efforts on capturing a staging area for a possible
invasion of the Japanese home islands. The U.S. Joint Chiefs identified Okinawa as
the most logical objective to establish this staging area. “The decision is ultimately made that Okinawa
is not only closer to the mainland of Japan, but also has large means for ships that can
be part unloaded. And it has a potential for airfields in it's
that much closer to Kyushu and the Japanese defenses that are being prepared at that time.” Within six months, U.S. forces gathered off
the coast of Okinawa readying themselves for multidomain operations. Multidomain operations are the combined arms
employment of joint and Army capabilities to create and exploit relative
advantages to achieve objectives, defeat enemy forces, and consolidate gains on behalf of
joint force commanders. They accomplish this with the four tenants
of Agility, Convergence, Endurance and Depth. The U.S. invasion of Okinawa to occurred in
three phases. Phase One began on 26 March, six days before
the main assault by the Seventy-Seventh Infantry Division, with landings on the Kerema Islands
off the southwest coast of Okinawa—launching Operation ICEBERG. Phase One then concluded with a demonstration
in the south by the Second Marine Division, the main landing on Okinawa by the Marine’s
Third Amphibious Corps and the Army’s Twenty-Fourth Corps, and the seizure of the airfields at
Yontan and Kadena. Phase Two featured landings on Ie Shima and
the occupation of northern Okinawa. Phase Three involved the seizure of nearby
islands. The main landing on Okinawa on 1 April was
the largest amphibious assault in the Pacific Theater during the Second World War. On L-Day, Tenth Army landed on the Hagushi
Beaches and began to cut the island in two. With a lack of opposition on the shores, Tenth
Army seized the Phase One objectives of Kadena and Yontan airfields within hours of landing. This permitted U.S. commanding general Lieutenant
General Simon Bolivar Buckner Jr. to start Phase Two—the seizure of all of Okinawa. The Seventh Infantry Division, for example,
crossed the island quickly and made it all the way to Hill one-six-five, known as Castle
Hill. Planners estimated it would take ten days
to achieve this objective. It had taken only a few hours. Weak opposition and rapid gains encouraged
U.S. commanding general Lieutenant General Simon Bolivar Buckner Jr. to proceed immediately
with Phase Two of the plan—the seizure of Okinawa. The Sixth Marine Division advanced up the
Ishikawa Isthmus and by 7 April had sealed off the Motobu Peninsula. By 13 April, the Second Battalion, Twenty-Second
Marine Regiment, reached Hedo Point at the northernmost tip of the island. The Marines had contained the bulk of the
Japanese forces in the north. Opposition in the south increased as American
Soldiers advanced into the interior of the island. The Japanese Thirty-Second Army defended Okinawa. Formed in March 1944, and commanded by Lieutenant
General Mitsuru Ushijima, the Army’s primary goal was to defend Okinawa and delay the Americans’
advance to the Japanese mainland. Throughout the latter part of 1944 and into
1945, Imperial Japanese Headquarters, or IJHQ, constituted and reinforced the Thirty-Second
Army on the island. The Thirty-Second controlled six airfields
on Okinawa and nearby Ie Shima. IJHQ estimated that the United States would
advance on the Home Islands through the Philippines, Formosa, or Okinawa. Japanese planners immediately marshaled ground
forces toward each location in hopes of delaying the U.S. advance. Within months, the Thirty-Second Army on Okinawa
grew in strength from approximately fourteen thousand to about one-hundred ten thousand
troops. The main combat units were the Twenty-Fourth
Division—a heavy division with organic artillery and three infantry regiments, each with three
battalions; the Sixty-Second Division, a light division with two brigades, each with five
infantry battalions, but no artillery; the Forty-Fourth Independent Mixed Brigade; and
the Twenty-Seventh Tank Regiment. The Okinawa Naval Base Force was also attached
to Thirty-Second Army. The Naval Base Force had one torpedo boat
squadron, one midget submarine unit, and various coastal defense, engineer, signal, supply,
transportation units normally used to support naval vessels in and around Okinawa. The Army also conscripted local Okinawans
for combat and non-combat roles. Male students aged fourteen and older were
organized into “Blood and Iron for the Emperor Duty Units” and trained for guerrilla warfare. The Japanese were ready to defend the island. Initially, General Ushijima intended to defend
Okinawa’s beaches against Allied amphibious landings. After learning from their experiences on other
Pacific islands, IJHQ urged him to reconsider. Imperial leadership understood Okinawa’s
strategic value lay in delaying the Americans from reaching the other home islands. “One of the one of the narratives that tends
to get overlooked in the Pacific War, and I think it's an important one. The United States Navy has been conducting
a submarine campaign since December 7th, 1941, its unrestricted naval campaign, and they
have done a masterful job of sinking the Japanese merchant fleet.” With losing some of his promised reinforcements
to submarine attacks, Ushijima concluded that the smaller Thirty-Second Army could not defeat
the Tenth Army on or near the beaches, but it could lure American forces into more advantageous
terrain and a prepared, deliberate defense. Thus, Ushijima defended fortified positions
in the hills and valleys of southern Okinawa. Colonel Hiromichi Yahara, Ushijima’s Senior
Operations Officer, described the strategy as attritional, aimed at delaying U.S. forces,
and inflicting maximum losses in men and matériel. Holding the Okinawa “fortress” as long
as possible would give the Imperial Japanese Army more time to fortify the Home Islands
and prepare for the expected U.S. invasion. The Imperial Japanese soldier was fighting
for the emperor and his life had no meaning outside of that of the Emperor. And he was willing to die in defense of the
Emperor and Chrysanthemum throne. There's a fundamental difference between the
Japanese soldier and the American Soldier slash Marine, and how he viewed the worth
of his life. For the average Japanese soldier, he's not
going home. And he knows he's not going home. Ushijima selected the southern half of the
island’s caves and ridges to defend in depth. The Thirty-Second Army reinforced the limestone
and coral caves in southern Okinawa with concrete and wood to create formidable defenses. The Thirty-Second Army also constructed a
complex tunnel system throughout the southern half of the island. Like the Fourteenth Area Army had done with
Manila’s sewers and Intramuros on Luzon, the Thirty-Second Army on Okinawa used tunnels
and Shuri Castle to assist in operations. Along with the fortified positions, the tunnels
served as strongpoints and formed Ushijima’s defense-in-depth. A strong point is a heavily fortified battle
position tied to a natural or reinforcing obstacle to create an anchor for the defense
or to deny the enemy decisive or key terrain. The Thirty-Second Army Headquarters operated
out of a tunnel complex under Shuri Castle. This historic place was the center of the
Naha-Shuri-Yonabaru Line, later known simply as the Shuri Line, and where the bulk of the
Thirty-Second Army, awaited the American attack. Commanders prepare a strong point for all-around
defense. Commanders establish a strong point when anticipating
enemy actions that will temporarily isolate a defending force that is retaining terrain
critical to the overall defense. The Shuri Line was a defense in depth. The Japanese forces defended in depth to absorb
the momentum of the planned U.S. attack by forcing the U.S. to attack repeatedly through
Japanese mutually supporting positions in depth. In a defense in depth, defending units are
arrayed in successive layers of battle positions along likely enemy avenues of approach. On the day of the U.S. invasion, 1 April 1945,
Japan’s Thirty-Second Army waited for the Americans inland, where Japanese troops had
prepared an area defense in strongpoints and three successive lines between Futema and
Kuba to the north and between Naha and Yonabaru to the south. The area defense is a type of defensive operation
that concentrates on denying enemy forces access to designated terrain for a specific
time rather than destroying the enemy outright. The focus of an area defense is on retaining
terrain where the bulk of a defending force positions itself in mutually supporting, prepared
positions. Units maintain their positions and control
the terrain between the enemy forces and the terrain they desire. Units at all echelons can conduct an area
defense. The Japanese Sixty-Third Brigade, Sixty-Second
Division manned the strongpoints and the first defensive line to delay and attrit the advancing
Americans. The division's main effort, the Sixty-Fourth
Brigade, dug in on reverse slopes of the defensive lines to destroy U.S. forces. The purpose of a reverse slope defense is
to deny the enemy the topographical crest. Although the defender may not occupy the crest
in strength, controlling the crest by fire is essential for success. This situation reduces the effects of indirect
fire (mortar, artillery, and close-air support) and draws the battle into small arms range. The reverse slope defense provides the defending
force an opportunity to gain surprise. The goal is to make the enemy commit
forces against the forward slope of the defense, causing enemy forces to attack in an uncoordinated
fashion across the exposed, topographical crest. The Twenty-Fourth Division was in defensive
positions covering potential landing sites on the south coast of Okinawa. The Forty-Fourth Independent Mixed Brigade
was south of Yonabaru and on the Chinen Peninsula. The Okinawa Naval Base Force occupied defensive
positions on the Oroku Peninsula. These Japanese units and the terrain they
occupied formed an extensive series of overlapping and mutually supporting defensive lines. Each area was filled with thousands of bunkers,
blockhouses, pillboxes, fortified caves, and tunnels. The defending Japanese forces used subterranean
systems to protect critical assets, develop covert programs, and maintain a form of initiative
against the more powerful U.S. forces. They also used subterranean locations for
command and control, defensive networks, operations, storage, production, and protection. If the Americans were going to secure Okinawa,
they needed to defeat the determined, and dug-in, Thirty-Second Army. A critical component of a successful amphibious
operation is the security of the fleet while the ground forces move inland. The United States Navy for its efforts is
not only providing air support for ground forces in terms of close air support and those
applications, as well as naval surface fire support. The United States Navy is also providing air
cover in terms of kamikaze protection. Unfortunately, the longer the amphibious support
element must remain on station and in harm’s way, the longer the combat forces of the fleet
must remain in position, engaged in the task of covering that element. There is no other support. The Japanese army, and navy, and air force
is stretched at this point. There is no large scale air fleet or naval
fleet that is going to come save them. And this is a bitter pill as some of the Japanese
commanders thought that they would get some naval support. But there's nothing there anymore. Indicative of what the Japanese had become
in terms of desperation in stemming this American offensive is they resort to using their largest
ship the Yamato. Which has basically been sitting portside
for most of the war as the Japanese have had a shortfall of fuel oil, ammunition, trained
crews. The Yamato really sits as a floating hotel
for a large part of the war. But in order to help with the defenses of
Okinawa, they will sortie it with the mission of it sailing to the island, beaching itself,
and being used as basically an artillery piece. The Americans are able to intercept it, and,
of course, through naval aviation sink the ship before it makes it to Okinawa. But it's indicative of the desperation the
Japanese are at. At Okinawa, those combat forces were the fast
carriers of Task Force Fifty Eight, and the enemy activity was primarily in the form of
suicide attacks. Japan created Special Attack Units that consisted
of both air and naval forces which were manned by airmen and sailors that would sacrifice
their lives by directing their aircraft and sea craft to crash
into American ships. The most dangerous Special Attack Units were
the aircraft from both the Japanese Navy and Army, known as the Kamikaze. Under the Japanese Ketsugo, or decisive operatons,
their mission is to bleed the Americans as much as possible. They know the Americans are casualty averse
and don't have the same ethic in terms of the honor of dying for the emperor. Or dying for the president in the American
parlance. So what they're hoping to do is bleed the Americans as much as possible to get some kind of negotiated settlement. The kamikazes are part of this. And the way the Japanese conduct their defensive is part of this. Every man is expected to give his life for the emperor. And the kamikazes are just the latest expression
of that. They do cause damage to the American fleet. However, given the size and scope of the American
military at this time, it really doesn't make a decisive difference. It makes a psychological difference. And it does play in the minds of naval air
crewmen and the surface ships themselves. However, the kamikazes themselves are not
going to stem the tide. But again, they're looking to affect the American
psychologically, not necessarily materially. With the pilot serving as a guidance system, one could frame IJHQ's Kamikaze aircraft over Okinawa as human-guided munitions. These served as a forerunner to modern precision-guided munitions, which are a necessity for the Army's MDO doctrine. They also continuously sent smaller attacks which kept the U.S. fleet on constant alert. Regular dive bomb and torpedo attacks were also mixed into Kamikaze sorties to make them even more unpredictable and deadly The Japanese executed almost two thousand Kamikaze and hundreds of conventional attacks, which resulted in damaging, and sinking, dozens U.S. ships. Back on land, the Sixth Marine Division cleared
northern Okinawa while the Army’s Ninety-Sixth and Seventh Infantry Divisions moved across
the island and away from the landing beaches. The Army divisions eventually located the
enemy in heavily fortified positions along Ushijima’s defensive lines. This extensive interlocking network of caves
and tunnels posed a serious challenge to the Americans. When dealing with a subterranean environment
The preferred course of action is to mitigate the underground facility, its portals, or
its effects, and to continue with the unit’s original mission. Several options exist to mitigate the underground
facility’s effects on mission accomplishment. These options include bypass, neutralize,
control, and contain. Additionally, commanders may choose to clear
a facility. However, an attack to clear an underground
facility may be deemed necessary. The Americans’ rapid advance and sweeping
gains had come to an end. The Ninety-Sixth Infantry Division encountered
fierce resistance in west-central Okinawa from Japanese troops holding fortified positions
east of Highway Number One, on what became known as Cactus Ridge, about eight kilometers
northwest of Shuri Castle. The Seventh Infantry Division encountered
similarly fierce Japanese opposition from a thirty-foot coral spire, known later as
“The Pinnacle.” By the night of 8 April, American troops had
cleared these and several other fortified positions. They suffered over one thousand five hundred
casualties in the process and killed or captured about four thousand five hundred Japanese. Yet the battle had only begun, for these
were merely outposts guarding the Shuri Line. At the Pinnacle and Cactus Ridge, the Americans
faced a situation that was to be repeated many times on Okinawa. The enemy had fortified the coral and limestone
ridges and prepared gun positions on the reverse slope of the hills. Using these tactics, the forward units of
the Thirty-Second Army stalled the U.S. Army’s Twenty-Fourth Corps’ offensive for another
eight days. The next American objective was Kakazu Ridge,
two hills with a connecting saddle that formed part of the Shuri Line’s outer defenses. Most of the Ninety-Sixth Infantry Division
focused on the ridgeline immediately north of Kakazu Village. In the face of concentrated Japanese counterattacks
and artillery fire from the reverse slope, repeated attempts on Kakazu Ridge failed,
even when supported by joint fires. The Ninety-Sixth advanced no farther than
the northeast slopes. It had taken Twenty-Fourth Corps fifteen days
to seize terrain initially projected to take only five days. Since the landings and Phase One progressed
quickly, they were only three days behind their earlier projection. Yet the losses were high. By 15 April, approximately one-thousand-two-hundred
replacements from Tenth Army reached the Seventh and Ninety Sixth Infantry Divisions by way
of Saipan. These replacements filled less than half the
combined U.S. losses, over three thousand casualties. After days of little progress and heavy casualties,
Tenth Army committed its reserve, the Twenty-Seventh Infantry Division, on 9 April. Commanded by Major General George W. Griner,
the Twenty-Seventh took-up positions along the west of the Ninety-Sixth Infantry Division’s
front line facing Kakazu Ridge. Twenty-Fourth Corps, under General John R.
Hodge, now had three divisions engaged instead of two. The Ninety-Sixth was in the center of the
line, with the Seventh to the east. As the American assault against Kakazu Ridge
stalled, Lieutenant General Ushijima, influenced by his Chief of Staff, Lieutenant General
Isamu Chō, decided to take the offensive. On the evening of 12 April—with severely
limited illumination under overcast skies—the Japanese Thirty-Second Army attacked American
positions across the entire front. Signal flares preceded an intense artillery
barrage. In one instance, two hundred rounds struck
one company of the Seventh Infantry Division’s area of operations in just five minutes. The Japanese counterattack was heavy, sustained,
and well organized. After fierce close combat, the attackers withdrew,
only to repeat their offensive the following night. The American were able to repulse the attacks
and employ a hasty defense after naval illumination fires finally exposed the Japanese counterattacking
forces. These attacks cost the Japanese over one thousand
six hundred killed and four captured. The Thirty-Second Army’s failed counterattacks
led the staff to conclude that the Americans were vulnerable to night infiltration tactics,
but superior American firepower made any Japanese offensive operation too costly. Therefore the Japanese reverted to their defensive
strategy. At dawn on 16 April, General Andrew Bruce’s
Seventy-Seventh Division began landing on the island of Ie Shima off the northwest coast
of Okinawa. Originally, the capture of Ie Shima and the
capture of the northern part of Okinawa was scheduled for Phase Two of the operation,
but the Marines’ rapid progress in the North encouraged General Buckner to merge Phases
One and Two. Ie Shima, similar to Keramas in the south,
contained an additional airfield that could be used to support the assault on Okinawa
and future strikes against the Japanese homeland. The Japanese had recognized Ie Shima’s value
and fortified the island between January and March 1945, using approximately two thousand
Japanese troops and hundreds of civilian laborers. Seventy-Seventh began their amphibious assault
on Ie Shima using the same techniques previously perfected in the Pacific Theater—battleships,
cruisers, destroyers, and other fire support ships targeted the beaches and aircraft attacked
with bombs, rockets, and napalm. Unlike the landings on Okinawa, the Japanese
defended some of the beaches on Ie Shima, and the Americans met increasing resistance
as they advanced on the island. General Bruce requested reinforcements in
an attempt to seize the island as quickly as possible, but Tenth Army could not provide
any—as the rest of Twenty-Fourth Corps was assaulting Kakazu Ridge. The Seventy-Seventh was on its own. The Japanese on Ie Shima fought the Americans
for every piece of the island. After several days of heavy fighting, the
Seventy-Seventh finally secured Ie Shima on 21 April. They suffered over one thousand casualties,
including the loss of the renowned war correspondent Ernie Pyle, who was killed by machine gun
fire on 18 April while on his way to the front. Pyle was buried in the division's cemetery
on Ie Shima under a crude marker which the Division later replaced with a monument. Concurrently, the fight for Kakazu Ridge on
Okinawa continued. Following the failed Japanese counterattack
and subsequent withdrawal to their next defensive line, General Hodge planned to break through
the enemy’s defenses around Shuri Castle. He envisioned his troops seizing the low valley
and highway extending across the island between Yonabaru and Naha. For this, the Twenty-Seventh Infantry Division
served as the supporting effort and attacked into Machinato on 18 April. Minutes after 1600 on 18 Apil, concealed by
artillery smoke, G Company, One Hundred Sixth Infantry Regiment crossed the estuary in engineer
assault boats. They scaled the cliffs on the other side and
cleared the Japanese fighting positions. By midnight, they erected a one hundred-seventeen-meter
footbridge and began moving toward the Naha-Yonabaru Road. The Seventh Infantry Division also supported
the effort by seizing Hill One-Seven-Eight and then advancing down to the Naha-Yonabaru
Road. The Ninety-Sixth Infantry Division was the
main effort and advanced toward the Shuri Line. On 19 April, General Hodge initiated the offensive
with a barrage of three-hundred twenty-four artillery pieces, the largest ever in the
Pacific Theater. U.S. Army artillery fired nineteen-thousand
rounds into the enemy’s lines in forty minutes. Battleships, cruisers, and destroyers joined
the bombardment; followed by Navy and Marine aircraft attacking the Japanese positions
with napalm, rockets, bombs, and machine guns. Yet, the Japanese defenses were positioned
on reverse slopes, where the defenders were protected from the typhoon of steel, emerging
from the caves to attack the Americans advancing up the forward slope with mortars and grenades. A tank assault by Company A, One-Ninety-Third
Tank Battalion—which included flamethrower equipped Shermans—attempted to outflank
the Japanese forces defending Kakazu Ridge. The company failed to link up with its infantry
support and lost twenty four tanks in five hours to Japanese antitank guns, mines, and
suicidal attacks by Japanese soldiers with satchel charges. Twenty-Fourth Corps suffered over seven hundred
casualties in a single day of fighting. The Japanese continued fighting for five days
after the American’s initial attack. But on the evening of 23 April, General Ushijima
ordered his severely degraded units to withdraw. During the night of 23-24 April, under heavy
fog and cover of artillery fires, the Sixty-Third Brigade, Sixty-Second Division
evacuated their remaining positions. Twenty-Fourth Corps now secured their L-plus
fifteen Objective Line, eleven days behind schedule. Both the Seventh and Ninety-Sixth Infantry
Divisions had been in combat for twenty-five consecutive days. They needed reconstitution in order to continue
offensive operations. Since Third Amphibious Corps had largely secured
northern Okinawa, the Marines were able to reinforce the offensive in the south. The First Marine Division relieved the Twenty-Seventh
Infantry Division, and the Seventy-Seventh Infantry Division relieved the Ninety-Sixth. When the Sixth Marine Division arrived, the
Third Amphibious Corps took over the right flank and Tenth Army assumed command and control
of current operations. Reconstitution operations are extraordinary
actions that are planned and implemented to restore a unit’s combat effectiveness. Reconstitution restores combat power to the
levels necessary to maintain endurance and continue operations. Reconstitution is not a sustainment operation
although sustainment plays an integral part. All sustainment functions are executed during
reconstitution. Human resources, medical, supply, and maintenance
personnel work closely with maneuver forces to rebuild combat power. Reconstitution consists of two major elements—reorganization
and regeneration. Reorganization is the expedient cross-leveling
of internal resources within an attrited unit in place to restore necessary combat effectiveness
and maintain endurance. Regeneration is the intentional restoration
of a unit’s combat power that requires time and resource intensive operations which includes
equipment repairs and replacements, supply replenishment, mission essential training,
and personnel replacements in accordance with the theater commander's guidance. After the bloody fights at Kakazu and Ie Shima,
Twenty-Fourth Corps was ready to renew the offensive, but as Ninety-Sixth Infantry Division
continued its advance south, it halted to assess the severely restricted terrain to
its front. The long-sheer cliff facing the division was
the Maeda Escarpment, or as the Americans later called it, “Hacksaw Ridge.” The escarpment runs northeast to southwest, dividing
southern Okinawa. Here the Japanese had prepared complex battle
positions, to include subterranean positions, to halt the American advance. A complex battle position is a defensive location
designed to employ a combination of complex terrain and engineer effort, such as camouflage,
concealment, cover, and deception to protect the unit from detection and attack while denying
its seizure and occupation by the enemy. A subterranean complex battle position is
further defined as a complex battle position with significant subterranean supporting infrastructure. A threat may integrate subterranean complex
battle positions into their main defense forces for an area defense. The additional subterranean component strengthens
the durability of the position and limits intelligence collection from the site. Subterranean complex battle positions share
many of the same characteristics of a complex battle position with a couple of additions. These characteristics are as follows:
· Limited avenues of approach to a subterranean, complex battle position. · Avenues of approach are easily observable
by the defender. · 360-degree fire coverage and protection
from attack. · Engineer effort prioritizing camouflage,
concealment, cover, deception measures, and countermobility efforts to disrupt attacks. · Large logistical caches. · Sanctuary from which to launch local attacks
and counterattacks. · Increased survivability. · Concealed subterranean facilities hinder
the ability of friendly forces to gather accurate damage assessments and other information. On 30 April the Seventy-Seventh Infantry Division
was ready to assume the attack on the Maeda Escarpment, and the Japanese met them with
over one thousand rounds of artillery and mortar fire on their front-line positions. Like at Kakazu, the Twenty-Fourth Corps’
attack stalled. Even though the Seventy-Seventh made some
progress in the center, the First Marine Division was halted on the west, and Seventh Infantry
Division was stalemated in the east Kochi Ridge. The defending Sixty-Second Division was at
half strength. The Japanese offset this numerical disadvantage
by preparing a deliberate defense that took advantage of the forbidding terrain. They held the high ground, compelling U.S.
forces to attack uphill. Learning from weeks of tenacious fighting
on Okinawa, the U.S. Soldiers and Marines modified their tactics. They used heavy weapons to suppress or neutralize
small areas, and then pushed a small salient into the Japanese lines. They developed new cave-fighting tactics and
techniques; employed artillery, tanks, and a combination of flamethrowers and explosives
to destroy the enemy’s complex battle positions. Despite these new tactics, techniques, and
procedures, U.S. forces were only able to make limited progress advancing at Hacksaw
Ridge. During one of the most brutal attacks, an
Army medic rescued seventy-five of his wounded
comrades. For his actions, Corporal Desmond T. Doss,
a conscientious objector, was awarded the Medal of Honor. Facing the collapse of another defensive line,
the Japanese leaders disagreed on the potential courses of the action. Cho advocated for a large-scale counterattack. Yahara insisted on defensive attrition. Ushijima eventually sided with Cho—convinced
that a successful assault targeting American supply lines would be a decisive blow in battle. The Japanese goal for the second counteroffensive
was to destroy the Twenty-Fourth Corps and neutralize the U.S. Navy in a series of coordinated
attacks. Ushijima ordered a land attack with amphibious
assaults, with simultaneous kamikaze and air attacks against the fleet. Over the third and fourth of May, Japanese
forces sank or damaged seventeen ships, inflicted over six hundred naval casualties, and bombed
shore installations including Yontan Airfield. On 4 May, the Thirty-Second Army attempted
amphibious assaults behind American lines. To support these assaults, Japanese
artillery moved out of their caves and into the open. By doing so, they were able to conduct preparatory
fires with thirteen thousand rounds in support, but effective American counterbattery fire
destroyed nearly sixty Japanese artillery pieces. The Americans were again able to conduct a
hasty defense and defeat the amphibious assaults. By midnight on 5 May, Ushijima accepted the
fact that his counterattack had failed. The Japanese forces had suffered massive casualties,
with over seven thousand dead in a matter of hours. The air attack had also cost the Japanese
the loss of one hundred thirty-one aircraft. With thousands of casualties and vital ammunition,
artillery, and equipment expended in the disastrous counterattack, the Japanese resumed their
attritional approach—just as Yahara recommended. By this point in the battle, the Americans
had suffered more than twenty thousand casualties. Six weeks of nearly continuous fighting resulted
in ever-increasing cases of combat fatigue. The American forces had extended their line
at Maeda, Kochi, and Awacha, thus making their lines of communication more secure and
gaining more favorable terrain. With these gains, Tenth Army launched another
offensive on 11 May. Two days later, American troops captured the
formidable Nishihara—better known as Conical Hill. Rising one hundred forty-five meters above
the Yonabaru coastal plain, this key terrain was the eastern anchor of the main Japanese
defenses and was occupied by about one thousand Japanese troops. Meanwhile, on the opposite coast, the First
and Sixth Marine Divisions secured Sugar Loaf Hill. The capture of these two key positions exposed
the Japanese around Shuri Castle on both sides. Estimating that the Thirty-Second Army had
expended most of their reserves in the counterattack, Buckner planned to commit all of Tenth Army. The area near Shuri Castle is the most rugged
terrain in the southern part of the island. Escarpments, steep slopes, and narrow valleys
make the major hill masses ideal terrain to establish a strong defense. Here, the Japanese Thirty-Second Army chose
to make its stand, meeting the enemy on its own terms in a series of concentric positions,
where minor infantry actions and antitank ambushes would be more successful and American
naval fire support less effective. General Buckner planned a double envelopment
of Shuri Castle by simultaneously maneuvering around both flanks of Ushijima’s force. He designated the Third Marine Amphibious
Corps as the main effort, and the Twenty-Fourth Army Corps as the supporting effort. These two Corps now made up the Tenth Army’s
front line. The Marines’ axis of advance was west of
the Shuri Line. The Seventy-Seventh Infantry Division fixed
the defending enemy units. The Ninety-Sixth enveloped the Shuri Line
from the east. For this operation, artillery employed point
fires, instead of area fires. The area fires used in earlier engagements
were considered to be ineffective by the Americans. The complex Japanese
defensive positions required the Americans to change from attacking larger terrain features
to small fighting positions. With this new approach, the Tenth Army slowly,
yet methodically destroyed the remaining Japanese defenses of the Shuri Line. Monsoon rains in May slowed the Americans’
progress and turned southern Okinawa into a quagmire. The torrential rains and overcast skies also
limited Tenth Army’s ability to observe ongoing operations from the air. Facing a double envelopment of his forces,
Ushijima ordered a withdrawal. During the night, the Thirty-Second Army evacuated
its wounded and supplies, and signal units started the process of establishing the new
headquarters. On 26 May, aerial observers identified large
troop movements just below Shuri Castle. At first, Buckner expected the Japanese,
without skilled men or adequate transportation or communications to be hindered by the
rain and poor roads, and he planned to take advantage of the retreat. But the rain and mud also affected Tenth’s
Army’s offensive. The Japanese retreat, although harassed by
artillery fire, was conducted with great skill at night. The Thirty Second Army moved nearly thirty
thousand personnel into its last defensive line farther south. On 28 May, patrols from the First Marine Division
found recently abandoned positions. The next morning, the First Battalion, Fifth
Marines occupied the heights east of the foreboding Shuri Castle and reported that it appeared
undefended. Shortly afterward, the battalion occupied
the fortification, which was outside the First Marine Division’s assigned area of operations. Only frantic efforts by the commander and
staff of the Seventy-Seventh Infantry Division prevented an American air and artillery strike
on the castle, which could have resulted in a tragic friendly fire incident. The Seventy-Seventh then moved in to secure
the rest of Shuri Castle. The Shuri Line was finally in American hands. Concurrently, from 24 to 27 May, the Sixth
Marine Division occupied the deserted ruins of Naha—Okinawa’s capital and largest
city. The Americans now sought the destruction of
the Thirty-Second Army. South of Shuri Castle, the terrain is rough,
but there are a few large escarpments. There are some broad valleys and an extensive
road network able to facilitate troop movements. Precipitous limestone cliffs surround an extensive
plateau at the southern end of Okinawa. On the northern side of the plateau are two
major hills—Yuza-Dake and Yaeju-Dake—which cover and provides visibility of all approaches
from the north, east, and west. These peaks were roughly six and half kilometers
from the original front line and had been seen by U.S. troops since the start of the
campaign. Here, Ushijima’s Thirty-Second Army braced
for its final defense. After their withdrawal from Shuri Castle,
eleven thousand uniformed troops and approximately twenty-two thousand non-uniformed defenders
readied themselves along the escarpment. Additionally, there were over ten thousand
Soldiers and four thousand Sailors at the Imperial Japanese Navy underground headquarters
near the Okinawa Naval Base. On 4 June, elements of the Sixth Marine Division
launched an amphibious assault on the peninsula. The majority of the Japanese sailors, including
Admiral Minoru Ōta, died by suicide within the tunnels of the underground naval headquarters
on 13 June. By 17 June, U.S. forces had pushed the remnants
of Ushijima’s shattered army into a small pocket in the far south of the island. On 19 June, Tenth Army accepted the surrender
of three hundred forty-three Soldiers, the first mass Japanese surrender of that size
in the Second World War. Though the numbers of surrenders greatly increased
after 19 June, more than two-thirds of the remaining Japanese defenders chose
to die by combat or suicide. At the beginning of June, Japanese casualties
averaged one thousand per day. By 21 June, that number had risen to four
thousand per day. As the battle drew to a close, American casualties
also continued to mount. General Buckner did not live to see the end
of the battle for Okinawa. On 18 June, Japanese artillery fire killed
Buckner while he monitored Tenth Army’s progress from a forward observation post. Marine Major General Roy Geiger, now the senior
commander, assumed temporary command of the Tenth Army until Army General Joseph Stilwell
arrived in theater five days later. The Americans continued to push the Japanese
Army closer to the coast. And in the early morning of 22 June, General
Ushijima and his senior officers gave up the fight and committed seppuku—ritual suicide—outside
a cave that faced the sea. Ushijima ordered Colonel Yahara not to commit
suicide, so he could tell the Imperial leaders how the Thirty-Second had defended Okinawa. That same day, Tenth Army held a flag-raising
ceremony to mark the end of organized resistance on Okinawa. It took seven more days to clear out the last
Japanese defenders. On 2 July, Tenth Army declared Okinawa secure–forty-eight
days longer than estimated. The official surrender ceremony was held on
7 September near Kadena Airfield. The battle for Okinawa was over. Forty-nine thousand American casualties and
the brutal fighting that occurred on Okinawa, gave military planners great trepidation about
Operation Olympic, the planned invasion of the Japanese island of Kyushu. On Okinawa, a single Japanese army, with scarce
logistics resupply, negligible air support, and limited reserves had successfully delayed
a significantly larger, combined arms force with strong logistics support for nearly three
months. Planners predicted U.S. units would have to
face an even more adaptive and determined enemy defending Kyushu and the even more important
main island of Honshu. Yet the horrors of the battle for Okinawa
did not dissuade the Americans from preparing for Operation Olympic.
