The Defense Of Guam

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By MajGen Haruo Umezawa and Col Louis Metzger

Originally published in the Marine Corps Gazette in August 1964

The battle to recapture Guam ended at noon, 15 August 1944, after a tough 25 days for both forces. Here's the Japanese account of the action, based on an official Japan Self Defense Force report. Its use as a basis for this article was authorized by Gen Keizo Hayashi, Chairman, Joint Staff, JDA.

AIDED by air attacks, which had commenced two days earlier, the naval force quietly moved inshore shortly after midnight on 10 December 1941. Under the cover of darkness the South Seas Detachment of the Imperial Japanese Navy commenced landing at several points on Guam. By noon of that day the landing force had "occupied all key areas of the island; resistance was light except for a small engagement on the northwestern beach." Thus fell the only US Naval Base located among the Japanese mandated islands. With this threat removed, the assault force joined the surge to the south, leaving the defense of Guam to a garrison unit of 150 officers and men. Once again quiet returned as Guam slipped into the backwash of the war.

The next six months favored the advancing Japanese forces. Then in a suddenly launched amphibious attack, the US forces struck back at Guadalcanal in August 1942. As the allied offensive in the South Pacific gained momentum, the Japanese Imperial General Headquarters was forced to reappraise the value of the islands of the Central Pacific. Until then these islands had been considered only as "key points of the patrol network" to provide security for the homeland. Their defense had not even been considered. Now it was essential that this policy be reexamined. Islands in the Central Pacific centering around the Marianas Islands were designated the "main battle position" and their status changed to that of a "main defense line" athwart the avenue of US attack. US war strategy was now obvious. The new Japanese counter-strategy was "to firmly secure the islands in the Central Pacific with army ground forces, deploying naval land-based carrier aircraft on these islands and to destroy the US fleet, along with its carrier striking forces, in a great naval battle."

First priority to receive defense forces went to the forward islands (Gilbert Islands, Marshall Islands and Nauru Island). However, by the end of 1943, the United States unleashed, with overwhelming force, a new offensive in the trans-central Pacific. With the crumbling of these outer defenses, the attack on the Marianas Islands became just a question of time.

In early February 1944 the 29th Division stationed in Manchuria (a reserve division for the Kwantung Army) and the 6th Expeditionary Force, newly organized in Manchuria, were ordered to Guam.

The 29th Division, the most efficient division of the Kwantung Army, had been undergoing "antiSoviet" combat training. Upon receipt of a movement order on 18 February, this division left its station area (Hai-cheng, Liao-Yang, and Tiehling) on the pretext of a long-term maneuver. Their horses were left behind, ammunition was distributed, and the troops supplied with summer uniforms and issued special equipment "for use in South Seas battle fields." The 29th Division embarked and sailed from Pusan, Korea.

The voyage was uneventful and the troops, long accustomed to the winter bleakness of Manchuria, were enjoying the warming sun of the tropics, in spite of the crowded conditions of the transports. Suddenly Sakito Maru carrying the 18th Infantry Regiment was hit by a torpedo fired BY USS Trout. It is doubtful if the skipper of Trout realized the terrible damage he had wrought as he continued his war patrol. The commanding officer and 2,200 of the 3,500 men embarked were lost, as were eight tanks and most of the artillery and heavy equipment. It was a loss that the defenders of Guam were to feel acutely.

The second major unit dispatched to Guam was Maj Gen Shigematsu's 6th Expeditionary Force composed of six infantry and two artillery battalions and two companies of engineers. After its arrival on Guam toward the end of March it was reorganized into the 48th Independent Mixed Brigade and the 10th Independent Mixed Regiment. Now the major elements to defend Guam were in place.

LtGen Takeshi Takashina, Commander of the 29th Division and also the Commander of South Marianas Area Group, had the mission of defending the vital areas of the Mariana Archipelago, south of Rota. He was faced with major problems. The news from the outer ring of defense was not good-the Gilberts and the Marshall Islands had either fallen or were sealed off by the advancing US Forces. It could only be concluded this wave of fire would soon be washing the shore of his domain. His staff believed the US could mount an assault of from four to five divisions, in two separate landing areas, supported by almost unlimited gunfire and air support. Takashina's means were meager. The total strength of his defense force was 21,000 men, of which 2,500 were Navy. Combat equipment and fighting materials were extremely limited and prior to the arrival of his forces no defenses or fortifications had been constructed. Only one airfield, Sumay on Orote Peninsula, was operational and that could be used only by fighter aircraft. Toto Airfield, scheduled for use by attack planes ("Ginga") was only at the stage of "ground leveling." Yet he was mindful of the instructions he had received in Japan prior to his departure from the Chief of the Imperial Army General Staff:

"The Mariana Islands are Japan's final defense line. Loss of the Islands signifies Japan's surrender."

This was a terrible burden, considering the trend of events and the means at hand.

Takashina had another small problem. Gen Hideyoshi Obata, the 31st Army Commander, and Commander of the Marianas Area, had been inspecting the Palau area in early June when the US forces launched the attack on Saipan. He and his staff departed by air for his headquarters on Saipan, but were forced to land and remain on Guam due to absolute command of the air by the US. Obata's and Takashina's relations were exact and correct, yet it was difficult to have an extra command structure imposed just prior to a decisive battle. Fortunately, although the Army and Division commanders occupied the same command post, the Division commander had a free hand in preparing for and conducting combat operations. He in turn was scrupulous in keeping the Army commander informed, and in accepting his advice and guidance.

Time was short and there was much to do. A careful estimate of the situation was made, and from it the Japanese defenders were able to derive the most probable landing areas. The basic defense plan was to organize two widely separated defense sectors. The northern area centered on Asan and was defended by the 29th Division (48th Brigade and 18th Regiment). The western sector centered on Agat and was defended by the 38th Regiment. As had the Marine defenders of Wake Island, they planned to hold their fire until the decisive minute so as to avoid premature disclossure. Only dummy positions were constructed on the beach as the defenders realized beach defenses would soon be destroyed. Behind the beach real and dummy positions for both automatic weapons and artillery were constructed so as to take every advantage offered by the terrain. On order from the Imperial General Headquarters, the "defeat-the-enemy-on-the-beach" principle was adopted. But Gen Takashina hedged to the extent that he held sufficient force out in order to constitute a reserve as a counterattack force. It was his concept that defense in depth was essential as protection against the withering US fire, and that victory could be gained by early and decisive counterattacks. Minefields were laid and offshore obstacles were constructed. All the while an intensive training program was carried out, counterattack plans developed, and troops brought to a high state of readiness. No force is ever completely ready for combat, but the Japanese defenders of Guam would rate high by any standard.

U.S. Preparations

At the same time the forces for the defense of Guam were moving into position, officers of the III Amphibious Corps were at Pearl Harbor developing a plan for the recapture of Guam (code name: STEVEDORE). According to this plan, the III Amphibious Corps (strength about 30,000) was to land simultaneously at two points on the western shore of Guam. In the northern sector the 3d Marine Division would land between Adelup Point and Asan Point, and in the western sector the 1st Provisional Marine Brigade and III Corps Artillery would land between Agat Point and Bangi Point. These two forces were to advance immediately and establish a force beachhead line along the commanding ground linking Adelup Point, Mt. Tenjo, Mt. Alifan, and Facpi Point. The seizure of Apra Harbor and Orote Peninsula was to be completed as rapidly as possible to expedite the early development of Guam for subsequent operations.

At the end of the Saipan operation, the senior Navy and Marine Corps commanders of the Guam Attack Force inspected the battle area. Captured Japanese documents and interrogations results revealed that Guam was fortified more strongly than Saipan. As a result, the 77th Infantry Division (Reinforced) (19,245 troops) was added to the Guam Attack Force and the scale of preparatory bombardment was intensified.

The Attack

Like a great, growling beast rising up out of the sea the Iron Typhoon arrived. Starting with intermittent shelling and air attacks, the tempo soon increased to a body and soul shaking crescendo. Destroyers shelled Agana Bay, Asan Point, and Agat Bay daily with five-inch guns. Destroyer Division 6 and Carrier Division 24 conducted combined air and surface operations; each took over the attack of one-half of the island and alternated at noon each day. Soon battleships and cruisers joined in the bombardment. Four battleships, three cruisers, and three destroyers were firing from off Asan Point and two battleships, three cruisers, and three destroyers from off Agana Bay. In all, 5,172 tons of shells were fired into Japanese positions during the 13 days preceding the landing.

Full-scale air attacks began on 6 July. Air strikes were made on coastal batteries, antiaircraft batteries, supply depots, airfield facilities, and other targets.

"The naval gunfire and air attacks were devastating. Most of the beach defenses were destroyed. All the palm trees along the seashore were mowed down. Every building known to the enemy was subjected to converting fire and intersections of roads were bombed. At night, motor vehicles engaged in transportation became targets of radar-controlled naval bombardment. Radio stations were fired upon in less than a minute after they started sending signals. The naval bombardment and aerial bombing was most intensive in Agana Bay and in the strip of land between Asan Point and Adelup Point. About half of the positions located in the northern and southern parts of Agat and on Adelup Point were destroyed. In the Agana area, every structure but the church was completely demolished. At Pago, Inarajan and Merizo, all road bridges were destroyed and the movement of motor vehicles and artillery became impossible."

From the intensity and concentration of the naval gunfire and air attacks the Japanese commanders decided the landing would most probably be in the area between Asan Point and Adelup Point. To meet the expected landing Gen Takashima ordered the Adelup Point area reinforced by one battalion, and the 10th Mixed Regiment to move from the east coast to an area south of Agana. In spite of the intense fire, defense preparations continued: torpedoes were buried on the expected landing beaches and anti-tank mines laid; anti-tank ditches were improved as were off shore obstacles; gasoline bombs were prepared for use against tanks; and special squads were readied to fire torpedoes from landing barges.

Japanese anti-aircraft artillery fired 5,000 rounds and reported they had downed some 780 US planes. They were awarded a letter of commendations for this "remarkable feat." With only eight rounds left for each AA gun they ceased firing at planes and reserved the little ammunition left for later use against tanks.

That anything was accomplished under the terrific shelling and air attack of the US naval forces is remarkable. In the words of a survivor,

"The bombardment had far-reaching effects on the morale of Japanese troops and also seriously restricted their ground activity; the continuous naval and aerial attacks not only obstructed the daytime work around positions, transportation activities, and the movement for reserve units, but also produced a serious demoralizing effect on personnel. There were occasional cases where the mental power declined sharply in a matter of a few days under continued enemy attacks. By the day preceding the enemy landing, some of the men had virtually become dazed after a week of continuous bombardment. On the other hand, there were others who, like lunatics, exhibited increasing moral strength under enemy fire. In other words, this shelling and bombing which was the heaviest in the history of World War II, was near the limit bearable by humans."

The morning of 21 July was humid, warm, and clear. With first light the sporadic gunfire of the night quickened and US Navy ships closed with the shore to destroy remaining targets in the beach areas. Aircraft dived in repeated attacks, neutralizing the Japanese defenses and preventing the movement of Japanese troop units. A slight offshore breeze blew dirt and smoke toward the assembled assault force. Japanese troops watched silently from their fortifications on the high ground behind the beaches as the assault assembled. It was an impressive sight. More than 100 combat ships and 200 transports were seen off of Asan in the northern sector and an equal number were off Agat to the west. Over 1,000 aircraft were in the air pounding the defenses.

Now all the preparations for defense were at an end. The defenders would have to fight from the fortifications which remained, and with the weapons they had. They were determined to fight to the last man and to stop, or at least delay, the US seizure of Guam. They were relieved that the waiting was at long last over, that no longer would they have to take unrelenting bombing and gunfire with no chance of fighting back. It was time for action. It was hard to be optimistic, but they were confident they would acquit themselves well.

As the US landing forces closed to the beaches, the naval gun fire and air attacks moved inland. The Japanese forces were quick to respond by raining fire from automatic weapons, mortars, and mountain artillery on the advancing Marines. LVTs and LVT(A)s were disabled and burning all along the reef and beaches. Mines knocked out three Marine tanks. In the Agat area to the west, Japanese artillery fired on US transports, forcing them to make smoke and put to sea. All this, as Gen Takashina had expected, was not enough. The coordinated attack of US forces, supported by devastating fire and air support, forged ashore and two beachheads were established. In both sectors the fighting was intense. The headquarters of one Japanese infantry battalion was attacked by two companies of Marines. Realizing the situation was critical the battalion commander, waving his sword, led his troops in a bayonet attack. He killed several Marines, but in turn he and most of his men were killed. So it was all along the front. Japanese artillery opened up from hidden positions, only to be knocked out by US fire. Japanese casualties during this first day were heavy. Although they had fought well, and still held most of the main positions on the high ground and the points covering the landing beaches, they had lost about half of their engaged personnel.

Colonel Suyenaga of the 38th Regiment, defending the Agat sector, had seen his regiment badly mauled in the fighting. His 1st Battalion and his artillery had sustained heavy losses. He realized that every moment of delay would permit the Marines to strengthen their position. He determined to envelop the enemy and win posthumous fame leading his remaining two battalions in an all-out night attack to destroy the enemy on Agat beach. Suyenaga phoned his division commander of his plan requesting approval of the attack. The division commander knew the overall battle situation and fully appreciated that the regiment was a key holding force in the Agat section, and his left flank. He refused the request but Suyenaga persisted until the division commander reluctantly gave permission for the counterattack.

At dusk the US forces dug in for the night. Their tanks moved into the front lines to take up the defense and star shells illuminated the front. Fire fights between small units from both sides continued all night. The Japanese took advantage of the lull to move reinforcements up and to reposition their forces. Not so with Col Suyenaga. After the approval of his division commander to make an all-out attack, he regretfully burned his regimental colors in the presence of his staff. At twilight he led his troops forward under heavy artillery and mortar fire. His regiment met and repulsed an enemy unit and advanced toward a small hill. Here he was severely wounded in the thigh by a mortar fragment. Undaunted, Suyenaga remained in tactical command until killed by a bullet through his chest. His troops, inspired by their leader and determined to crush the enemy, dashed forward to engage the Marines "and virtually all the attacking force perished."

On the second day of the landing the pressure of the attacking forces continued unabated. In the Asan beach area the 21st Marines slowly forced their way to the high ground; while the 9th Marines swung to the right to take Cabras Island and get into position to seize the part of Apra Harbor in their zone of action. Colonel Ohashi's 18th Regiment holding the left flank of this sector was slowly forced back. His Military Academy classmate, Brigade Commander Shigematsu of the 48th Independent Mixed Brigade, holding the Japanese center and right flank, was favored with more defensible terrain. There heavy casualties were inflicted on the 3rd Marines. They were forced to inch their way slowly up the heavily defended Chonito Cliff.

Eight miles to the west in the Agat landing area the Japanese 38th Infantry was fighting the battle alone. (American control of the air and overwhelming firepower made it impossible for other Japanese units to assist them, even if they had strength to spare.) This unit, weakened by the losses sustained in Col Suyenaga's night attack, faced the assaulting troops of the 1st Marine Brigade and troops of the 77th Infantry division (US Army) being fed into the battle. Mt. Alifan fell this second day of the ground action as constant US pressure continued.

Logistics problems were making their weight felt on the defenders. Ammunition and food were carried to the Japanese troops on the backs of service units and by a unit organized from the Japanese residents of Guam. Water was the major problem. During, this period there was no rain. The one small stream running in the northern sector was stained with blood and polluted from the bodies of dead soldiers lying in the water.

By the third day of the battle Gen Takashina was forced to review the situation. In both sectors the Americans were breaking out of the beachhead. He knew the battle in the Agat Bay area was going poorly for his isolated 38th Infantry Regiment. The regimental commander had been killed along with many unit commanders. In addition the front line units had lost 70 percent of their troops. In his own sector (Asan-Adelup Point) the battle was also going against the Japanese. US forces were pushing forward and roads were being constructed to allow the Marines to use their overwhelming armored strength. Takashina was also concerned that the Marines might outflank his defenses with another landing in Alifan Bay to the east. His front line commanders were nearly all casualties and about 70 percent of his own front line troops had been lost. All his forces were low on ammunition. The superiority of US air and gunfire made any daylight action impossible. He concluded:

"That if such severe fighting, especially the enemy's severe incessant air strafing, continued for several successive days, it would deal a heavy blow upon our men psychologically and deprive them of all human functions, energy and will to fight. Some effective measure was urgently needed. No doubt, the effect of a crushing defeat in battle would be unimaginably great since the Japanese forces had never experienced defeat."

In his view this left him just two courses of action; an all-out counterattack under the cover of darkness; or disengagement and withdrawal to a defensive position in the jungle in the northern half of Guam. For him it was a hard decision. The counterattack was the conventional policy of the Imperial Army and in accordance with the Army's concept of "serving country at sacrifice of life." It also offered some chance of victory and the opportunity to strike before the US Forces were fully organized. The withdrawal for defense provided the possible advantage of securing a position on Guam as the base for a future Japanese offensive, which he believed was forthcoming. With his mission in mind he made his decision-attack. The time: night; the date was 25 July. The 18th Regiment, isolated in the Agat Sector, was too weak to do anything to influence the attack. It could barely slow the US advance. The attack had to be made with the elements which still survived from the 29th Division. The objective was to overwhelm the US forces and destroy them on the beach in the Asan Sector.

There was no heavy fighting on the 24th as both sides appeared to be resting for the next act. The Japanese made plans for the attack and complete disposition and preparations. Documents were burned and officers and men readied themselves. Ex-Col Takeda recalled:

"Officers and men were prepared to meet a heroic death as they were to launch the general attack. The most important of combat preparations was that of the mind. Of course, they had been prepared for death since the attack of the US forces because of possibility of being shot dead any time. The word Gyokusai (death for honor) came to be spoken among them.

"Some took out photographs of their parents, wife, or children and bid farewell to them; some prayed to God or Buddha, some composed a death poem and some exchanged cups of water at final parting with intimate comrades. All pledged themselves to one another to meet again at the Yasukuni Shrine. Their psychological state is not understandable except to comrades who pledged to one another to share their fate. Under these circumstances, people attain the highest reach of spirit; even those who have never believed in Shintoism or Buddhism naturally become spiritually enlightened, and all people become composed. Therefore, they become able to judge things calmly and act properly.

"However, as life is the most cherished thing for man, it was not possible for all the officers and men to attain complete enlightenment. Namely, some were struck with fear, as they wanted to save their lives. Even those who, usually looking composed, believed to be fine soldiers, were struck with some fear to the last; few were able to be ready to rush out through the enemy line courageously. However, all of the officers and men were generally prepared for their fate, because of their honor, sense of responsibility and hate for the enemy."

The Army Commander, Gen Obata, received a message from the Imperial General Headquarters on the decision for the general attack.

"We are deeply moved by your hard fighting continued day and night. You have decided to launch the general attack. We wish you and your men every success in the attack."

At sunset the Army and Division commanders proceeded to the front line and inspected the general situation of the battlefield and encouraged the officers and men on the front. They reached the division command post newly established on Mt. Mangan, heard detailed reports on preparations by units for the counterattack, and gave instructions on the general counterattack scheduled for that night. Although half the officers and men from the division headquarters had been killed, the remainder joined the attack. All the wounded who could walk also joined in the assault. Led by their remaining commanders the attacking forces rushed forward into a wall of machine gun and artillery fire. Although the Japanese lost over 3,000 men they were unable to break the Marines lines. The attack failed.

General Obata ordered those that remained to cease attacking and to withdraw to defensive positions. He then sent the following message to the Imperial General Headquarters:

"On the night of the 25th, the army, with its entire force, launched the general attack from Fonte and Mt. Mangan toward Adelup Point. Commanding officers and all officers and men boldly charged the enemy. The fighting continued until dawn but our force failed to achieve the desired objectives, losing more than 80 percent of the personnel, for which I sincerely apologize. I will defend Mt. Mangan to the last by assembling the remaining strength. I feel deeply sympathetic for the officers and men who fell in action and their bereaved families."

On the basis of the battle situation and instructions from Imperial General Headquarters Gens Takashina and Obata decided they had no choice but to withdraw their remaining force (an estimated 3,000 men) to the north and organize a defense in the Barrigade Hill-Finegayan area.

Led by tanks, the attacking US forces made the withdrawal all the more difficult. Japanese units fought bravely, but suffered heavy casualties. The 10th Mixed Regiment's commander Kataoka was killed. About 30 enemy tanks surrounded the 29th Division headquarters. Officers and men of the headquarters, organized into antitank assault units, attacked and destroyed three tanks. Having exhausted their ammunition, they fought desperately, climbing on enemy tanks with hand grenades in their hands, or stabbing enemies with bayonets. Dead bodies lay in heaps.

Gen Takashina took command of the fighting with perfect composure. He planned to break through the surrounding enemy tanks to continue fighting in the northern part of the island.

Together with Col Takeda, he stole out of the division headquarters, ran straight between some enemy tanks, and jumped from a small cliff. The US tanks fired volleys of tracer bullets at them but the two officers managed to escape into a dead space of the tank guns. By afternoon they reached a stream at the foot of Mt. Macajuna when Gen Takashina was shot through the chest by a machine gun bullet from a US tank. He died almost instantly.

With the division commander dead, Gen Obata, the Army Commander, look command of the remaining, forces. Fighting a delaying action, the Japanese forces attempted to slow the US advance. By 30 July Gen Obata, had reached the preselected defense position on Mt. Barrigade-Finegayan and found the position was unsuitable for fighting. The jungle was too thick for fields of fire and there was no room for counterattacks. Assigning a covering force under his Chief of Staff, Gen Tamura, to delay the US forces, Gen Obata directed an all-out effort to organize positions on Mt. Mataguac and Mt. Santa Rosa further to the north. Service units attempted to move supplies to the rear positions under the intense strafing of US planes. After fierce fighting the delaying position was overrun. The survivors of the covering force withdrew and joined the other defenders in the last defense position. Under the cover of heavy artillery and mortar fire the US tanks and infantry constantly pushed forward. By 10 August Gen Obata, an experienced soldier, could see the end. He personaly wrote last messages to the Emperor and the Imperial General Headquarters. In the latter he said:

"I accepted the important position of the Army Commander, and although I exerted all-out effort, the fortune of war has not been with me. The fighting has not been in our favor since the loss of Saipan. We are continuing a desperate battle on Guam. Officers and men have been lost, weapons have been destroyed and ammunition has been expended. We have only our bare hands to fight with. The holding of Guam has become hopeless. I will engage the enemy in the last battle with the remaining strength at Mt. Mataguac tomorrow, the 11th. My only fear is that the report of death with honor (annihilation) at Guam might shock the Japanese people at home. Our souls will defend this island 10 the very end; we pray for the security of the Empire.

"I am overwhelmed with sorrow for the families of the many fallen officers and men. I request measures be taken for government assistance to them. The remaining officers and men have high morale. Communications with homeland have been disrupted today, the 10th, after 1200. I pray for the prosperity of the Empire."

Messages dispatched, Gen Obata moved again to the front and calmly boosted the morale of the officers and men. He assembled scattered units and planned to launch a last attack on the morning of 11 August. Before this could be done the US forces again attacked killing all but three of his officers. Japanese troops returned the fire with machine guns and rifles but were soon "neutralized" and killed. Gen Obata had prepared for this moment. With dignity, and in the tradition of the Imperial Army, he took his own life with his pistol. The time was M35 on 11 August. Organized fighting of Japanese forces on Guam came to an end.

Japanese casualties were 18,377 killed and 1,250 POW. These forces, in the face of overwhelming US air and gunfire, defended the widest front held by any Japanese division in World War II.

With the advantage of 20 years hindsight, it is possible to make some observations on the Japanese defense of Guam. Like earlier US island defenses it was a case of too little too late. The Japanese moved defensive forces to Guam only four months before the US attack was launched. In fact, they arrived in March, when US planning for the Guam operation began. Just under 20,000 troops were pitted against nearly 50,000 US troops who enjoyed overwhelming naval gunfire and air superiority. This was at a time when the largest part of the Japanese army was not committed to action.

With no attempt to distract from the ability of the Japanese commanders, they were forced by Imperial General Headquarter's policy to "defeat-the-enemy-on-the-beach," and accepted battle on two widely separated, and not mutually supporting, fronts. Their fighting strength was sapped by Col Suyenaga's, and subsequent, counterattacks. These attacks, launched piecemeal, could only be indecisive. If Gen Takashina had defended the vital area of Guam, Apra Harbor, he would have seriously delayed subsequent US operations. By so doing he could have delayed the devastating B-29 raids on his homeland. Instead, he located his forces behind the landing areas and thus violated the cardinal rule of island defense-defend the vital area.