BETIO: ASSAULT OF AN ISLAND FORTRESS

Source Material Includes:

The Pacific Campaign by Dan van der Vat

Tarawa: A Battle Report by Irving Werstein

Tarawa: The Story of a Battle by Robert Sherrod

Introduction: The American capture of the island of Betio in the Tarawa Atoll proved to be a series of mistakes and mishaps. Victory came because the enemy was overwhelmed by Allied superiority in men, weapons and supplies. Japanese forces stubbornly gave ground and in general refused to surrender. Although costly, American mistakes were not forgotten and the Battle upon the small island fortress would provide American planners with priceless information on the technique of island fighting.

December 1941

Japan attacks the United States Fleet at Pearl Harbor. At the time of the attack the Japanese Fleet had overtaken the American Fleet in size and strength. United States President Franklin Delano Roosevelt addresses Congress with his "Day of Infamy" speech and signs a declaration of War against Japan. The United States enters the war. Japanese aggreession shortly leads to the capture and control of a large sphere of influence in the Pacific.

Japanese Soldiers invade and seize the British controlled Gilbert Islands including the Tarawa Atoll and the island of Betio. Their capture represented the Japanese south eastern most expansion in the South Pacific. The islands served as outposts on the eastern approaches to the Japanese controlled Marshall Islands. The islands also posed a threat to Allied communications between the Central and South Pacific.

October 1943

Admiral Chester Nimitz assembles a fleet of land, air and sea forces under Vice Admiral Raymond A. Spruance to invade and conquer the Japanese held Atolls of Tarawa and Makin in the Gilbert Islands. Nimitz believed capture of the Gilberts essential to any later invasion of the Marshall Islands. Without the Gilberts, an attack on the Marshalls would leave an invasion force susceptible to attack from the rear.

• The Fleet: The fleet was composed of over 200 ships including 17 carriers, 12 battleships, 8 heavy and 4 light cruisers, and 66 destroyers. The carriers held over 900 planes. For the land invasion, 3 dozen transport ships carried the 2nd Marine Division and elements of the 27th Infantry Division. The total land invasion force numbered 35,000 marines and soldiers.

• The Plan: Nimitz divided the armada into 3 task forces: the northern task force to assault the Makin Atoll; a southern force to capture the Tarawa Atoll; and the fast-carrier force to protect the other two forces. Tarawa: The primary objective within the Tarawa Atoll was the island of Betio. Betio was two miles long and a half mile wide at its widest. The Japanese Commanding Officer Rear Admiral Keiji Shibasaki located his headquarters and built an airstrip on the island.

• The Defenders: The Japanese force numbered over 4,800, including 2,600 soldiers, 1,000 Japanese Construction workers and 1,200 civilian laborers. The heavily fortified island comprised of a network of steel and concrete pillboxes, tunnels, and sea walls with 14 coastal defense guns and over 100 machine guns. The defenders were deeply entrenched and able to withstand American naval and air bombardment.

Following naval and air bombardment, Marines from the 2nd Marine Division land on Betio. The assault takes place on Red Beaches 1,2 and 3 located on the lagoon side of the island.

Map of Betio

• Initial assault: The plan was for the naval and air bombardment to continue right up until the marines hit the shore. The bombardment was to take out key Japanese defensive positions, keep the Japanese forces defending the island pinned down and provide cover for the advancing marines. However, the initial assault proved a disaster and the cover that the marines had counted on was lost due to a series of blunders by American forces. The naval and air forces failed to coordinate their schedules and the carrier planes arrived a half hour later than expected. The amtracs and Higgins boats got started late so that the naval bombardment stopped long before the landing craft approached the shore. This permitted Japanese defenders to emerge from their network of tunnels and fire on the approaching marines. A failure to adequately research the depth of the lagoon and coral reefs along it led to further disaster for the landing craft. Higgins boats became stuck on the coral reef below and became easy targets for the defenders. Marines inside them had to wade ashore unprotected and under constant machine gun and mortar fire. Battalions of the first marine waves suffered casualties as high as 75%.

12:00 pm

Situation Critical: Seeking reinforcements, General Julian Smith, commanding the marine invasion onto Betio radios General Holland Smith, "The issue is in doubt." General Holland Smith orders the 6th Marines combat team dispatched from Makin into the battle at Betio.

With reserves on the way and his marines locked in a vicious battle barely a few yards on the shore, General Julian Smith then orders his last reserve battalion, Major Hay's 1st battalion, into landing craft in preparation for reinforcement of the existing 5 battalions on the island. However, Hay's Battalion would not be ordered into the battle until the next morning. This meant the depleted units on the beachead would have to endure possible Japanese nighttime counterattacks without the help of the reserve force.

10:00 pm

By nightfall marine positions consisted of men along the pier and sea wall just a few yards away from the water. Communications were down and messages had to be relayed by runner. With their backs to the sea, the marines dug in and prepared for a Japanese counterattack. Fortunately for the marines, General Shibasaki's communication lines had been demolished during the day's initial bombardment. Without communications, the Japanese leader was unable to coordinate his troops for a successful counter attack on the marine beachhead. Shibasaki had lost an opportunity to recapture the marine position and drive the marines back into the sea.

D-Day plus 1

6:00 am

Major Hay's 1st Battalion is ordered into shore.

• Analysis: Another disaster. Hay's troops were immediately fired upon by Japanese mortars and machine gun fire. During the night, several suicide minded Japanese soldiers swam out to the wrecked American landing craft and set up machine guns. Troops on the shore were now being fired upon from the rear and Major Hay's approaching battalion was forced to endure assault without the benefit of strong cover. Another failure of American planners to study tide charts caused more Higgins boats to lock up on the coral reefs during high tide. Hay's rifle companies took over 40% casualties. Allied fighter straffing of enemy positions proved futile since the enemy was heavily entrenched in pillboxes and bunkers.

Higgins Boats

As the tide rolled in, so did the Higgins boats filled with badly needed supplies. While the marines were still pinned down on the beaches, supplies of ammunition, medical supplies and communication equiptment raised the beleagured troops morale. With communications restored and Major Hay's troops bolstering the American beachhead, the marines prepared for another assault and breakout. Marines on Red Beach 2 pushed their way across the airstrip and seized an inland foothold. At the same time, Major Ryan's forces on Red Beach 1 advanced toward Betio's southwest corner and cleared the area known as Green Beach. For the first time, a marine beachhead had been secured. This would prove vital to the assault as more men and supplies could come in unmolested. The marines were no longer just maintaining a foothold on the beach, now they were able to advance.

Dusk:

Having just arrived from Makin, the 6th Marines were ordered to land one battalion on Green Beach. Major William Jone's 1st Battallion arrived onshore, fresh and intact. Marine assault leader Colonel David M. Shoup radiod back, "We are winning." Tanks, artillery, supplies and men now arrived on Green Beach in increasing numbers. Without relief of fresh troops, supplies, planes, ships and submarines from the Imperial Japanese Fleet, Admiral Shibasaki's forces could not hold out indefinitely. His troops, however, defiantly fought on.

D-Day-plus-2

Morning:

American forces assault Shibasaki's headquarters.

With tank support, Major Crowe's mortars finally cracked open the Japanese pillboxes protecting Shibasaki's headquarters. Shibasaki's bunkers and the Japanese soldiers within them were exterminated with brutality typical of the Pacific Campaign. Grenades dropped into the bunker's air vents caused scores of Japanese soldiers to scramble outside, only to be cut down by canister shot and rifle fire. A marine bulldozer then covered the bunker in sand, entombing the inhabitants. Gasoline was then poured into the vents and TNT charges dropped inside. Over 200 charred bodies were eventually discovered when the marines entered the bunker.

Afternoon:

American forces link on the airstrip.

The arrival of 3rd Battalion, 6th Marine on Green Beach permitted Major Jone's fresh 1st Battalion to push along the southern shore of Betio and eventually link up with marines who had earlier crossed the airfield. By nightfall the Japanese airfield and entire western end of Betio had fallen to American forces. The remaining Japanese stronghold lie along a narrow strip of land on the eastern end of Betio.

Night:

Last Japanese counterattack.

Rather than wait to be overrun, the remaining Japanese forces made a suicidal charge against Major Jone's forces. The line held in deadly hand-to-hand combat. The last remaining Japanese stronghold on the island had been extinguished.

D-Day-plus-3:

1:10pm

Betio is declared secured and the first American aircraft land on the island's airstrip.

BETIO

Analysis: The American victory at Tarawa proved costly. Over 1,000 marines, Navy officers and men were killed and 2,300 men were wounded. The Japanese had fought stubbornly, preferring to die rather than surrender. Less than 150 Japanese soldiers and Korean laborers surrendered. The remaining 4,700 died while fighting or committed suicide rather than capture. On the homefront, criticism of "the Tarawa fiasco" called into question the armed forces Pacific Campaign. Amtracs, which suffered over 80% casualties on Betio, were soon strengthened with better armor and weaponry. Increased and refined aerial intelligence provided accurate data concerning tidal conditions and water depths for future amphibious invasions. Deeply entrenched enemies behind bunkers were now understood to be able to withstand mass aerial and naval bombardment. Precision bombing would be needed to destroy heavily fortified positions. However, the lessons learned at Tarawa helped save many lives in future island battles.