What if: a Japanese attack on Night One at Tarawa

EA Baker
Dec 2
12 min read

Dawn broke over Tarawa (Betio) on 20 November 1943, with a violence even the Pacific had not yet seen. The sun rose behind a thin veil of smoke drifting across Tarawa’s lagoon, blurring the silhouettes of LVTs charging forward while Higgins boats stall against the reef. Marines, weighed down with gear, were forced to climb over the sides of their landing craft and wade hundreds of yards through waist- to chest-deep water. All the while, Japanese pillboxes spat fire from the shoreline, filling the lagoon with lead and American blood.

A man in military uniform with medals, facing forward in a black-and-white photo. The expression is serious. The background is plain. The photo is of Rear Admiral Keiji Shibazaki, commander of the Japanese defense on Tarawa. — Photo of Rear Admiral Keiji Shibazaki, the Japanese commander in charge of defending Tarawa.

The Marines could see nothing but the splashes of rounds hitting the water, their fallen comrades floating in the seawater, and

stunted palms on the atoll afire from aerial and naval bombardment. And their crucible of fire had only just begun.

Betio was the most fortified atoll in the Pacific. The Japanese commander, Rear Admiral Keiji Shibazaki, had famously told his officers, “A million men couldn’t take [Tarawa] in a hundred years.” On that hellish morning, it would appear he might've been proven correct.

However, history records that Shibazaki never lived to see the night of the first day. A 5-inch naval shell struck his command as they were trying to relocate further back from the fighting, killing him and much of his senior staff. Without him, Japanese forces never mounted the one action American planners feared most: a coordinated night counterattack to throw the Marines back into the sea.

But what if that shell had missed its mark? What if Colonel Shibazaki had survived to issue an all-out banzai attack the night after the landings, when the American beachhead was most vulnerable?

This analysis explores that alternate timeline, exploring what might've happened if the Japanese had exploited the Marines’ fragile Day-1 perimeter, and how even a partial breakthrough could have caused problems for the Marines clinging to yards of sand.

What Actually Happened at Betio

To understand the counterfactual, we first need to anchor it in the real battle’s conditions.

Betio was anything but a lightly defended strip of coral; it was engineered into a death trap by Shibizaki. He had experience in amphibious landings in China. He understood the difficulties a landing force faced and how vulnerable they were in the opening stages of an operation of this kind.

He used his time in the buildup to the invasion wisely, constructing:

Reinforced coconut-log bunkers, some with 3–5 feet of overhead protection.
Honeycombed trenches to allow defenders to move unseen across much of the island (Major Henry Pierson "Jim" Crowe commented on the sudden appearance of Japanese defenders in positions he thought the Marines had cleared, saying "where the hell are they coming from? Do they have a tunnel to Tokyo or something?". Little did he know those sentiments were pretty accurate, given the Japanese trench system.
Mines, anti-boat obstacles, and interlocking machine-gun positions.
8-inch Vickers guns capable of reaching the lagoon approaches (bought by the Japanese before the war; there's a myth they were seized when Singapore fell, and that's not true).
Pillboxes, bunkers, and fighting positions lined the entire island.
Roughly 4,800 defenders, including Special Naval Landing Forces (these were sailors and are inaccurately called Japanese Marines; they were not Marines), cross-trained with Japan’s arsenal of weapons, occupied these defenses.

Map of Betio depicting beaches, defense positions, and Marine landings on Nov 20, 1943. Key shows gun types, posts, and buildings. — Map of Japanese defenses and US Marine landing beaches on Betio (Tarawa).

The fortress was designed to stop a seaborne assault in its tracks. For most of the first day, it was not going well for the Marines.

The Landing Chaos on Red Beach 1 and 2

Military officer in dress uniform with medals stands in front of flag. Wearing glasses, neutral expression. Wood panel background. — Portrait of General David M. Shoup, Medal of Honor recipient and 22nd commandant of the US Marine Corps (1960-1963).

The Marines’ plan hinged on timing the tides correctly. However, they did not have accurate tide tables for the island, relying on a few residents and locals who knew (and basing their predictions for Betio's tides on tides in Australia, Chile, and Samoa; not an ideal way to determine such a thing). Major Frank Holland, a New Zealand reserve officer with experience sailing those waters, warned US planners, particularly Colonel David M. Shoup, of how unpredictable the tides could be, which could mean the Higgins boats might get caught on the reef if there was not enough clearance. This would force the Marines to wade ashore under heavy fire from Japanese defenses.

Unfortunately, that’s exactly what happened. The tide was too low for Higgins boats to clear the reef (they needed 4 feet of clearance, but the neap tide left them with only 3). The LVTs had no problem traversing the reef with their tracks, but the invasion force did not have enough for every wave. By the time the assault waves reached the lagoon’s edge, dozens of boats were grinding to a halt. Marines had no choice but to leap into the water—some 300, 500, and, in some cases, 700 yards from shore. Others were able to transfer to an LVT to head on in, but the Japanese gunfire became more accurate, destroying some of these craft on the way in.

Soldiers in a boat and water, storming a beach under a smoky sky, with explosions in the distance. Mood is tense and chaotic. — Painting by Sergeant Tom Lovell, USMC, titled "Tarawa, South Pacific, 1943."

Japanese machine guns opened up immediately. Entire platoons went down in the water as radios shorted out. Unit cohesion quickly dissolved as it became a mad scramble to the shore. When on the sands, men crawled forward over dead and wounded, clinging to burned-out Amtracs, floating debris, the protruding pier, and the seawall that lined the beach.

By nightfall, the Marines had only claimed small slivers of the beach with some men's feet still touching the water's edge. As such, the situation was quite precarious as a cohesive line did not connect the three beaches. Instead, they were held by pockets of marines amid the dead and wounded of the first day. It was, in sum, barely a toehold. But the Marines were luckier than anyone would think, given what they had just endured.

Japanese Communications Collapse

The U.S. naval bombardment was not perfect (it was supposed to be the largest of the war but fell significantly short of the original promise). However, while the bombardment would wreak havoc on the Marine communications, it would also do so on the Japanese.

Telephone lines running between bunker complexes were severed across the island. Some outposts were cut off entirely from central command. Though most of the Japanese defenders survived the bombardment in their deep log bunkers, their ability to coordinate large-scale movements was severely impaired.

In short, the Japanese still had the strength for a counterattack, but lacked the command structure and the ability to coordinate through effective communications to execute it.

The Death of Shibazaki

Mid-afternoon on 20 November, Shibazaki attempted to relocate his staff after U.S. fire spotted their position. As the colonel and his officers moved through an open stretch between bunkers, a 5-inch naval shell landed nearly on top of them. Shibazaki, along with much of his senior staff, was killed instantly.

A naval ship, numbered 559, sails on the ocean with another ship following. It carries many people, under a cloudy sky. — USS Dashiell (DD-659), a Fletcher-class destroyer, underway in the Pacific circa 1943. Dashiel and USS Ringgold (DD-500) both provided naval gunfire support to the US Marines ashore in the lagoon. It's unclear which ship's fire killed Shibazaki and his command.

This moment sealed the Japanese defenders’ fate. Without unified leadership or functioning communications, they never executed the kind of coordinated night attack that their doctrine—and their culture—favored.

Instead, the garrison fought with discipline but without operational cohesion. The Marines slowly ground them down. But remove a single shell from history, and that might‘ve changed the battle.

The Shell That Never Hits

As Shibazaki’s party moves to their new position, what if the shell misses its mark? Maybe the shell falls short, and the explosion shakes the ground, hurls debris, and kills several adjutants—but Shibazaki survives with only minor injuries as his staff drags him behind cover. They complete their relocation successfully, leaving Shibazaki in command. With their lines cut, he would've had to rely on runners to coordinate a night action.

Shibazaki, known for his aggressive mindset, had trained his men to destroy an amphibious beachhead at the water's edge. Japanese night assaults, though rarely successful against American firepower, were often devastating when launched against disorganized or exhausted enemy forces (these tactics were more successful in China than when used against the Americans, but there are instances of the threat they pose, as seen at places like Attu and Saipan).

And few American formations were ever more vulnerable than the Marines on Betio after Day 1. With communication partly restored and his staff alive, Shibazaki probably would’ve issued orders to prepare for a coordinated counterattack during the first night to dislodge the Marines.

A Coordinated Counterattack

After Day 1, the Marines barely held their beachhead. Marines were scattered, exhausted, soaked, and low on ammunition. Platoons were isolated, and many leaders were dead. No tanks remained on many parts of the line. The beachhead had gaps wide enough for entire squads of enemy infiltrators to exploit (which were sent in the night in our timeline). After day one, thousands of Japanese sailors remained ready and willing to fight to the last, waiting for orders. In this alt timeline, the order comes.

Shibazaki Issues the Charge

From his reconstructed command post, Shibazaki orders his surviving officers to:

Concentrate forces along the Red 2 and Red 3 hinge—where the Marines are most disorganized (assuming they have this intelligence).
Move units through trench networks to attack from multiple points.
Launch in the middle of the night, probably between 0100 and 0200.

Japanese troops assemble quietly in the maze of log bunkers and trenches. Officers pass final instructions along whisper-chains. At 0155, the island goes eerily silent before the attack.

The Assault Unfolds

The stillness is shattered by screams of BANZAI! as hundreds of Japanese soldiers surge from the coconut-log defenses. Machine guns erupt along with small arms fire. Grenades arc through the darkness, illuminating the frightened faces of Marines. The first wave slams into the thin Marine lines on Red 2.

Soldiers charge with rifles and bayonets on a beach at night; explosions light up the water, palm trees silhouetted against a dark sky. — **Banzai charge during the Guadalcanal Campaign. 1942-43. August 2015. Illustrator: Peter Dennis (Osprey Publishing).**

Close-quarters combat erupts instantly—knives, entrenching tools, and rifle butts are put to use. Marines fire flares, turning the beachhead into a patchwork of stark light and deep shadow. Under star shells, the Marines would revert to naval gunfire support to stymie the onslaught and turn the tide.

Despite these desperate attempts to hold, the Japanese exploit the gaps in the American line, driving a wedge between the beaches. In response, the Marines form desperate, ad hoc defensive lines. At least one Japanese assault reaches the lagoon side of the beachhead, threatening to divide it entirely.

Decaying artillery gun amid rubble and debris in a barren landscape, sky overcast. Scene conveys desolation and aftermath of destruction. — A destroyed eight-inch Vickers gun on Betio.

Despite chaos, the 2nd Marine Division was filled with veterans of previous campaigns. Their discipline holds as they fight for their lives—still, the Japanese break into several positions, triggering brutal hand-to-hand fights. As the eastern sky begins to lighten, the battle devolves into a maze of isolated pockets. Marines retake lost ground yard by yard. Japanese units, lacking ammunition and expecting no retreat, fight to the last. By sunrise, the line holds—but the Marines are mauled. Casualties would inevitably be much higher, and reinforcements would have to be deployed first thing on Day 2.

In our timeline, a mistake happens. Elements of the 8th Marines were supposed to come ashore at the undefended Green Beach and instead landed at Red 2, where the Japanese are still entrenched. Many of them are cut down before they reach the shore. What remains of these reinforcements, joining with Marines already ashore, would need to push forward and knock out "the Pocket" to move inland. In such a situation, the casualties would be higher, the battle timeline would probably extend, and the fighting would continue to grind on until the bitter end.

Red 2 Foothold collapses

If the Japanese had completely broken through to Red 2, it would've split the Marine foothold on the island in two, isolating the Marines on Red 1 and Red 3. In such a situation, the Marines would have to retake Red 2, as that position would be tactically untenable. Until that happens, it's possible Red 2 would be closed, and a new beachhead would be opened beside Red 1 (designated Green Beach) as Marines retake Red 2. This would be the worst-case scenario, for I don't believe the Japanese would've been able to throw the Americans back into the sea entirely. If that happened, it would truly be a disaster, setting back the Central Pacific Drive and raising all sorts of questions back home.

Strategic Consequences Across the Pacific War

Even if the Marines eventually prevail, a successful Japanese night counterattack would have major ripple effects.

Tarawa was already controversial—graphic footage shocked the American public. A near-failure or catastrophic Day-2 setback could lead to:

Create a firestorm of criticism in Congress.
Trigger formal investigations into Nimitz and amphibious doctrine.
Leads to hesitation about the Central Pacific strategy.
Possibly delay operations in the Marshalls, shifting the entire timetable of the Pacific War.

And if such a setback happened, would FDR even approve the release of Norm Hatch and his team's footage in the film With the Marines at Tarawa (assuming they survive the battle)?

Americans were not accustomed to steep casualty lists for single battles. To avoid panic and a potential propaganda victory for Japan, the government may opt to keep a tighter lid on what happened at Tarawa.

Military Ripple Effects

The U.S. Marine Corps and Navy would implement sweeping changes to their approach to amphibious assaults. Some changes were made in our timeline, but a failure or near disaster may amplify those changes, which would include:

An increase in LVTs rather than using Higgins boats for future operations in the Pacific.
Revised tide calculation protocols (Underwater Demolition Teams, or UDTs, the precursor to the US Navy SEALS, do come out of the actual battle to scout beaches ahead of invasions).
Stronger and longer pre-invasion bombardments (the Tarawa bombardment was terribly short).
More caution and preparation at Kwajalein, Eniwetok, Saipan, and Tinian.

Tarawa was already a harsh lesson; in this timeline, the lesson becomes that much more magnified.

Japanese Morale and Strategy

For Japan, this may either underscore the importance of counterattacks on the night after the first day of an invasion or further accelerate the adoption of defense-in-depth tactics rather than attempting to defeat an invasion at the water's edge.

Such outcomes may include:

A partially successful banzai attack becomes a propaganda victory (assuming this information is not kept secret to prevent such an attack).
The defense of tiny Betio is cast as proof that night attacks could shatter American lines.
Garrison commanders in the Marshalls and Marianas potentially double down on banzai tactics to attack beachheads (or the inverse, depending on the specific Japanese commander).
Japanese planners delay any move away from massed night assaults.

While it wouldn’t change the war’s outcome, it might actually accelerate the attrition of Japanese defensive forces, shortening the duration of future operations as these forces expose themselves willingly to American firepower. At the same time, it may also expedite the adoption of defense in depth (as seen at Biak, Peleliu, and Iwo Jima) rather than trying to defend at the waterline, leading to bloodier battles sooner.

Final Reflection

History often turns on small moments. Betio was one of the most fragile amphibious beachheads the United States ever attempted to hold. For the Marines, the threat of a coordinated Japanese night attack was their worst nightmare, and with good reason: their lines were thin, scattered, and dangerously exposed.

In our timeline, a single shell ended any such idea of a night assault.

In another reality, the Battle of Tarawa might have stretched on for days, where the fate of a thousand Marines, and perhaps the momentum of the entire Central Pacific drive, hung in the balance.

On Betio, the trajectory of a single shell may have been all that separated a costly victory from an outright disaster.

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