THE FINAL CAMPAIGN: Marines in the Victory on Okinawa
by Colonel Joseph H. Alexander, USMC (Ret)
Assault on Shuri
The Tenth Army's Action Report for the battle of
Okinawa paid this understated compliment to the Thirty-second
Army's defensive efforts: "The continued development and improvement
of cave warfare was the most outstanding feature of the enemy's tactics
on Okinawa." In their decision to defend the Shuri highlands across the
southern neck of the island, General Ushijima and his staff had selected
the terrain that would best dominate two of the island's strategic
features: the port of Naha to the west, and the sheltered anchorage of
Nakagusuku Bay (later Buckner Bay) to the east. As a consequence, the
Americans would have to force their way into Ushijima's preregistered
killing zones to achieve their primary objectives.
Everything about the terrain favored the defenders.
The convoluted topography of ridges, draws, and escarpments served to
compartment the battlefield into scores of small firefights, while the
general absence of dense vegetation permitted the defenders full
observation and interlocking supporting fires from intermediate
strongpoints. As at Iwo Jima, the Japanese Army fought largely from
underground positions to offset American dominance in supporting arms.
And even in the more accessible terrain, the Japanese took advantage of
the thousands of concrete, lyre-shaped Okinawan tombs to provide combat
outposts. There were blind spots in the defenses, to be sure, but
finding and exploiting them took the Americans an inordinate amount of
time and cost them dearly.
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The bitterest fighting of the campaign took place
within an extremely compressed battlefield. The linear distance from
Yonabaru on the east coast to the bridge over the Asa River above Naha
on the opposite side of the island is barely 9,000 yards. General
Buckner initially pushed south with two Army divisions abreast. By 8 May
he had doubled this commitment: two Army divisions of the XXIV Corps on
the east, two Marine divisions of IIIAC on the west. Yet each division
would fight its own desperate, costly battles against disciplined
Japanese soldiers defending elaborately fortified terrain features.
There was no easy route south.
By eschewing the amphibious flanking attack in late
April, General Buckner had fresh divisions to employ in the general
offensive towards Shuri. Thus, the 77th Division relieved the 96th in
the center, and the 1st Marine Division began relieving the 27th
Division on the west. Colonel Kenneth B. Chappell's 1st Marines entered
the lines on the last day of April and drew heavy fire from the moment
they approached. By the time the 5th Marines arrived to complete the
relief of 27th Division elements on 1 May, Japanese gunners supporting
the veteran 62d Infantry Division were pounding anything that
moved. "It's hell in there, Marine," a dispirited soldier remarked to
Private First Class Sledge as 3/5 entered the lines. "I know," replied
Sledge with false bravado, "I fought at Peleliu." But soon Sledge was
running for his life:
As we raced across an open field, Japanese shells of
all types whizzed, screamed, and roared around us with increasing
frequency. The crash and thunder of explosions was a nightmare . . . .
It was an appalling chaos. I was terribly afraid.
General del Valle assumed command of the western zone
at 1400 on 1 May and issued orders for a major attack the next morning.
That evening a staff officer brought the general a captured Japanese
map, fully annotated with American positions. With growing uneasiness,
del Valle realized his opponents already knew the 1st Marine Division
had entered the fight.
Okinawan civilian is flushed from a cave into which a smoke grenade had
been thrown. Many Okinawans sought the refuge of caves in which they
could hide while the tide of battle passed over them. Unfortunately, a
large number of caves were sealed when Marines suspected that they were
harboring the enemy. Department of Defense Photo (USMC) 125697
The division attacked south the next day into broken
country there after known as the Awacha Pocket. For all their combat
prowess, however, the Marines proved to be no more immune to the
unrelenting storm of shells and bullets than the soldiers they had
relieved. The disappointing day also included several harbingers of
future conditions. First, it rained hard all day. Second, as soon as the
5th Marines seized the nearest high ground they came under such intense
fire from adjacent strongpoints and from higher ground within the 77th
Division's zone to the immediate southeast they had to withdraw. Third,
the Marines spent much of the night engaged in violent hand-to-hand
fighting with scores of Japanese infiltrators. "This," said one
survivor, "is going to be a bitch."
The Peleliu veterans in the ranks of the 1st Marine
Division were no strangers to cave warfare. Clearly, no other division
in the campaign could claim such a wealth of practical experience. And
while nothing on Okinawa could match the Umurbrogol's steep cliffs,
heavy vegetation, and endless array of fortified ridges, the "Old Breed"
in this battle faced a smarter, more numerous foe who had more artfully
prepared each wrinkle in the moonscape. In overcoming the sequential
barriers of Awacha, Dakeshi, and Wana, the 1st Marine Division faced
four straight weeks of hell. The funneling effects of the cliffs and
draws reduced most attacks to brutal frontal assaults by fully-exposed
tank-infantry-engineer teams. General del Valle characterized this small
unit fighting as "a slugging match with but temporary and limited
opportunity to maneuver."
"Ronson" tank, mounting a flame thrower, lays down a stream of fire
against a position located in one of the many Okinawan tombs set in the
island's hillsides. Department of Defense Photo (USMC) 122153
General Buckner captured the fancy of the media with
his metaphor about the "blowtorch and corkscrew" tactics needed for
effective cave warfare, but this was simply stating the obvious to the
Army veterans of Biak and the Marine veterans of Peleliu and Iwo Jima.
Flamethrowers were represented by the blow torch, demolitions, by the
cork screw but both weapons had to be delivered from close range
by tanks and the exposed riflemen covering them.
On 3 May the rains slowed and the 5th Marines resumed
its assault, this time taking and holding the first tier of key terrain
in the Awacha Pocket. But the systematic reduction of this strongpoint
would take another full week of extremely heavy fighting. Fire support
proved excellent. Now it was the Army's time to return the favor of
interservice artillery support. In this case, the 27th Division's field
artillery regiment stayed on the lines, and with its forward observers
and linemen intimately familiar with the terrain in that sector,
rendered yeoman service.
Marine Artillery at Okinawa
The nature of the enemy defenses and the tactics
selected by the Tenth Army commander made Okinawa the biggest battle of
the war for Marine artillery units. General Geiger landed with 14 firing
battalions within IIIAC; the total rose to 15 in June when Lieutenant
Colonel Richard G. Weede's 2/10 came ashore in support of the 8th
Brigadier General David R. Nimmer commanded III Corps
Artillery, and Lieutenant Colonel Curtis Burton, Jr., commanded the 2d
Provisional Field Artillery Group, which contained three batteries of
155mm howitzers and three of 155mm "Long Tom" guns. Colonel Wilburt S.
("Big Foot") Brown commanded the 11th Marines and Colonel Robert B.
Luckey, the 15th Marines. The Marine divisions had greatly enhanced
their firepower since the initial campaigns in the Pacific. While one
75mm pack howitzer battalion remained (1/11), the 105mm howitzer had
become the norm for division artillery. Front-line infantry units also
were supported by the 75mm fire of medium tanks and LVT-As, 105mm fire
from the new M-7 self-propelled "siege guns," 4.5-inch multiple rocket
launchers fired by the "Buck Rogers Men," and the attached Army 4.2-inch
Lieutenant Colonel Frederick R. Henderson described
this combination of fire support: "Not many people realize that the
artillery in Tenth Army, plus the LVT-As and naval gun fire equivalent
gave us a guns/mile of front ratio on Okinawa that was probably higher
than any U.S. effort in World War II."
General Buckner urged his corps commanders to
integrate field artillery support early in the campaign. With his corps
artillery and the 11th Marines not fully committed during the opening
weeks, General Geiger quickly agreed for these units to help the XXIV
Army Corps in their initial assaults against the outer Shuri defenses.
In the period of 7 April-6 May, these artillery units fired more than
54,000 rounds in support of XXIV Corps. This was only the beginning.
Once both Marine divisions of IIIAC entered the lines, they immediately
benefited from Army artillery support as well as their own organic fire
support. As one example, prior to the 5th Marines launching a morning
attack on the Awacha Pocket on 6 May, the regiment received a
preliminary bombardment of the objective from four battalions two
Army, two Marine.
By the end of the battle, the Tenth Army artillery
units would fire 2,046,930 rounds down range, all in addition to 707,500
rockets, mortars, and shells of five-inch or larger from naval gunfire
ships offshore. Half of the artillery rounds would be 105mm shells from
howitzers and the M-7 self-propelled guns. Compared to the bigger guns,
the old, expeditionary 75mm pack howitzers of 1/11 were the "Tiny Tims"
of the battlefield. Their versatility and relative mobility, however,
proved to be assets in the long haul. Colonel Brown augmented the
battalion with LVT-As, which fired similar ammunition. According to
Brown, "75mm ammo was plentiful, as contrasted with the heavier
calibers, so 1/11 (Reinforced) was used to fire interdiction, harassing,
and 'appeasement' missions across the front."
Generals Geiger and del Valle expressed interest in
the larger weapons of the Army. Geiger particularly admired the Army's
eight-inch howitzer, whose 200-pound shell possessed much more
penetrating and destroying power than the 95-pound shell of the 155mm
guns, the largest weapon in the Marines' inventory. Geiger recommended
that the Marine Corps form eight-inch howitzer battalions for the
forthcoming attack on of Japan. For his part, del Valle prized the
accuracy, range, and power of the Army's 4.2-inch mortars and
recommended their inclusion in the Marine division.
Defense Photo (USMC) 12446
On some occasions, artillery commanders became
tempted to orchestrate all of this killing power in one mighty
concentration. "Time on target" (TOT) missions occurred frequently in
the early weeks, but their high consumption rate proved disadvantageous.
Late in the campaign Colonel Brown decided to originate a gargantuan TOT
by 22 battalions on Japanese positions in the southern Okinawan town of
Makabe. The sudden concentration worked beautifully, he recalled, but "I
neglected to tell the generals, woke everyone out of a sound sleep, and
caught hell from all sides."
General Geiger insisted that his LVT-As be trained in
advance as field artillery. This was done, but the opportunity for
direct fire support to the assault waves fizzled on L-Day when the
Japanese chose not to defend the Hagushi beaches. Lieutenant Colonel
Louis Metzger commanded the 1st Armored Amphibian Battalion and
supported the 6th Marine Division up and down the length of the island.
Metzger's LVT-As fired 19,000 rounds of 75mm shells in an artillery
support role after L-Day.
The Marines made great strides towards refining
supporting arms coordination during the battle for Okinawa. Commanders
established Target Information Centers (TICs) at every level from Tenth
Army down to battalion. The TICs functioned to provide a centralized
target information and weapons assignment system responsive to both
assigned targets and targets of opportunity. Finally, all three
component liaison officers artillery, air, and naval gunfire
were aligned with target intelligence information officers. As
described by Colonel Henderson, the TIC at IIIAC consisted of the corps
artillery S-2 section "expanded to meet the needs of artillery, NGF, and
CAS on a 24-hour basis . . . . The Corps Arty Fire Direction Center and
the Corps Fire Support Operations Center were one and the same facility
with NGF and air added."
Such a commitment to innovation led to greatly
improved support to the foot-slogging infantry. As one rifle battalion
commander remarked, "It was not uncommon for a battleship, tanks,
artillery, and aircraft to be supporting the efforts of a platoon of
infantry during the reduction of the Shuri position."
At this point an odd thing happened, an almost
predictable chink in the Japanese defensive discipline. The genial
General Ushijima permitted full discourse from his staff regarding
tactical courses of action. Typically, these debates occurred between
the impetuous chief of staff, Lieutenant General Isamu Cho, and the
conservative operations officer, Colonel Hiromichi Yahara. To this
point, Yahara's strategy of a protracted holding action had prevailed.
The Thirty-second Army had resisted the enormous American
invasion successfully for more than a month. The army, still intact,
could continue to inflict high casualties on the enemy for months to
come, fulfilling its mission of bleeding the ground forces while the
"Divine Wind" wreaked havoc on the fleet. But maintaining a sustained
defense was anathema to a warrior like Cho, and he argued stridently for
a massive counterattack. Against Yahara's protests, Ushijima sided with
his chief of staff.
Marines of the 1st Division move carefully toward the
crest of a hill on their way to Dakeshi. The forwardmost Marines stay
low, off of the skyline. Department of Defense Photo (USMC)
The greatest Japanese counterattack of 4-5 May proved
ill-advised and exorbitant. To man the assault forces, Ushijima had to
forfeit his coverage of the Minatoga sector and bring those troops
forward into unfamiliar territory. To provide the massing of fires
necessary to cover the assault he had to bring most of his artillery
pieces and mortars out into the open. And his concept of using the
26th Shipping Engineer Regiment and other special assault forces
in a frontal attack, and, at the same time, a waterborne, double
envelopment would alert the Americans to the general counteroffensive.
Yahara cringed in despair.
the end, victory was achieved at Okinawa by well-trained assault troops
on the ground, like this Marine flamethrower operator and his watchful
rifleman. Marine Corps Historical Center
The events of 4-5 May proved the extent of Cho's
folly. Navy "Flycatcher patrols on both coasts interdicted the first
flanking attacks conducted by Japanese raiders in slow-moving barges and
native canoes. Near Kusan, on the west coast, the 1st Battalion, 1st
Marines, and the LVT-As of the 3d Armored Amphibian Battalion greeted
the invaders trying to come ashore with a deadly fire, killing 700.
Further along the coast, 2/1 intercepted and killed 75 more, while the
1st Reconnaissance Company and the war dog platoon tracked down the last
65 hiding in the brush. Meanwhile the XXIV Corps received the brunt of
the overland thrust and contained it effectively, scattering the
attackers into small groups, hunting them down ruthlessly. The 1st
Marine Division, instead of being surrounded and annihilated in
accordance with the Japanese plan, launched its own attack instead,
advancing several hundred yards. The Thirty-second Army lost more
than 6,000 first-line troops and 59 pieces of artillery in the futile
counterattack. Ushijima, in tears, promised Yahara he would never again
disregard his advice. Yahara, the only senior officer to survive the
battle, described the disaster as "the decisive action of the
of the 7th Marines wait until the exploding white phosphorous shells
throw up a thick-enough smoke screen to enable them to advance in their
drive towards Shuri. The smoke often concealed the relentlessly
attacking troops. Department of Defense Photo (USMC) 120182
At this point General Buckner decided to make it a
four-division front and ordered General Geiger to redeploy the 6th
Marine Division south from the Motobu Peninsula. General Shepherd
quickly asked Geiger to assign his division to the seaward flank to
continue the benefit of direct naval gunfire support. "My G-3, Brute
Krulak, was a naval gun fire expert," Shepherd said, noting the
division's favorable experience with fleet support throughout the
northern campaign. Unspoken was an additional benefit: Shepherd would
have only one adjacent unit with which to coordinate fire and maneuver,
and a good one at that, the veteran 1st Marine Division.
On the morning of 7 May General Geiger regained
control of the 1st Marine Division and his Corps Artillery from XXIV
Corps and established his forward CP. The next day the 22d Marines
relieved the 7th Marines in the lines north of the Asa River. The 1st
Marine Division, which had suffered more than 1,400 casualties in its
first six days on the lines while trying to cover a very wide front,
adjusted its boundaries gratefully to make room for the newcomers.
Heading south toward Shuri Castle, a 1st Marine Division
patrol passes through a small village which had been unsuccessfully
defended by Japanese troops. Department or Defense Photo (USMC)
Yet the going got no easier, even with two full
Marine divisions now shoulder-to-shoulder in the west. Heavy rains and
fierce fire greeted the 6th Marine Division as its regiments entered the
Shuri lines. The situation remained as grim and deadly all along the
front. On 9 May, 1/1 made a spirited attack on Hill 60 but lost its
commander, Lieutenant Colonel James C. Murray, Jr., to a sniper. Nearby
that night, 1/5 engaged in desperate hand-to-hand fighting with a force
of 60 Japanese soldiers who appeared like phantoms out of the rocks.
The heavy rains caused problems for the 22d Marines
in its efforts to cross the Asa River. The 6th Engineers fabricated a
narrow foot bridge under intermittent fire one night. Hundreds of
infantry raced across before two Japanese soldiers wearing satchel
charges strapped to their chests dashed into the stream and blew
themselves and the bridge to kingdom come. The engineers then spent the
next night building a more substantial Bailey Bridge. Across it poured
reinforcements and vehicles, but the tanks played hell traversing the
soft mud along both banks each attempt was an adventure. Yet the
22d Marines were now south of the river in force, an encouraging bit of
progress on an otherwise stalemated front.
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The 5th Marines finally fought clear of the devilish
Awacha Pocket on the 10th, ending a week of frustration and point-blank
casualties. Now it became the turn of the 7th Marines to engage its own
nightmare terrain. Due south of their position lay Dakeshi Ridge.
Coincidentally, General Buckner prodded his commanders on the 11th,
announcing a renewed general offensive along the entire front. This
proclamation may well have been in response to the growing criticism
Buckner had been receiving from the Navy and some of the media for his
time-consuming attrition strategy. But the riflemen's war had progressed
beyond high-level exhortation. The assault troops knew fully what to
expect and what it would likely cost.
Marine Tanks at Okinawa
The Sherman M-4 medium tank employed by the seven
Army and Marine Corps tank battalions on Okinawa would prove to be a
decisive weapon but only when closely coordinated with
accompanying infantry. The Japanese intended to separate the two
components by fire and audacity. "The enemy's strength lies in his
tanks," declared Lieutenant General Mitsuru Ushijima before the
invasion. Anti-tank training received the highest priority within his
Thirty-second Army. These urgent preparations proved successful
on 19 April when the Japanese knocked out 22 of 30 Sherman tanks of the
27th Division, many by suicide demolitionists.
The Marines fared better in this regard, having
learned in earlier campaigns to integrate infantry and artillery as a
close, protective overwatch to their accompanying tanks, keeping the
"human bullet" suicide squads at bay. Although enemy guns and mines
took their tool of the Shermans, only a single Marine tank sustained
damage from a Japanese suicide foray.
Lieutenant Colonel Arthur J. Stuart commanded the 1st
Tank Battalion during the Okinawa campaign. The unit had fought with
distinction at Peleliu a half-year earlier, despite shipping shortfalls
which kept a third of its tanks out of the fight. Stuart insisted on
retaining the battalion's older M-4A2 Shermans because he believed the
twin General Motors diesel engines were safer in combat. General del
Valle agreed: "The tanks were not so easily set on fire and blown up
under enemy fire."
By contrast, Lieutenant Colonel Robert L. Denig's 6th
Tank Battalion preferred the newer M-4A3 model Shermans. Denig's tankers
liked the greater horsepower provided by the water-cooled Ford V-8
engine and considered the reversion to gasoline from diesel an
acceptable risk. The 6th Tank Battalion would face its greatest
challenge against Admiral Minoru Ota's mines and naval guns on Oroku
The Sherman tank, much maligned in the European
theater for its shortcomings against the heavier German Tigers, seemed
ideal for island fighting in the Pacific. By Okinawa, however, the
Sherman's limitations became evident. The 75mm gun proved too light
against some of Ushijima's fortifications; on these occasions the new
M-7 self-propelled 105mm gun worked better. And the Sherman was never
known for its armor protection. At 33 tons, its strength lay more in
mobility and reliability. But as Japanese anti-tank weapons and mines
reached the height of lethality at Okinawa, the Sherman's thin-skinned
weak points (1.5-inch armor on the sides and rear, for example) became a
cause for concern. Marine tank crews had resorted to sheathing the sides
of their vehicles with lumber as a foil to hand-lobbed Japanese magnetic
mines as early as the Marshalls campaign. By the time of Okinawa,
Marine Shermans were festooned with spot-welded track blocks, wire mesh,
sandbags, and clusters of large nails all designed to enhance
Defense Photo (USMC) 123166
Both tank battalions fielded Shermans configured with
dozer blades, invaluable assets in the cave fighting to come, but
surprisingly neither outfit deployed with flame tanks. Despite
rave reports of the success of the USN Mark I turret-mounted flame
system installed in eight Shermans in the battle of Iwo Jima, there
would be no massive retrofit program for the Okinawa-bound Marine tank
units. Instead, all flame tanks on Okinawa were provided courtesy of
the U.S. Army's 713th Armored Flamethrower Battalion. Company B of that
unit supported the IIIAC, with brand-new H-1 flame tanks. Each carried
290 gallons of napalm-thickened fuel, good for two-and-a-half minutes of
flame at ranges out to 80 yards. The Marines received consistently
outstanding support from this Army company throughout the battle.
The Marines employed the newly developed T-6 "Tank
Flotation Devices" to get the initial assault waves of Shermans ashore
on L-Day. The T-6 featured a series of flotation tanks welded all
around the hull, a provisional steering device making use of the tracks,
and electric bilge pumps. Once ashore, the crew hoped to jettison the
ungainly rig with built-in explosive charges, a scary proposition.
The invasion landing on 1 April for the 1st Tank
Battalion was truly "April Fools Day." The captain of an LST carrying
six Shermans equipped with the T-6 launched the vehicles an hour late
and 10 miles at sea. It took this irate contingent five hours to reach
the beach, losing two vehicles on the reef at ebb tide. Most of Colonel
Stuart's other Shermans made it ashore before noon, but some of his
reserves could not cross the reef for 48 hours. The 6th Tank Battalion
had better luck. Their LST skippers launched the T-6 tanks on time and
in close. Two tanks were lost one sank when its main engine
failed, another broke a track and veered into an unseen hole but
the other Shermans surged ashore, detonated their float tanks
successfully, and were ready to roll by H plus 29.
Japanese gunners and mine warfare experts knocked out
51 Marine Corps Shermans in the battle. Many more tanks sustained
damage in the fighting but were recovered and restored by hard-working
maintenance crews, the unsung heroes. As a result of their ingenuity,
the assault infantry battalions never lacked for armored firepower,
mobility, and shock action. The concept of Marine combined-arms task
forces was now well underway.