Did later campaign assessments conclude Tarawa should have been isolated and bypassed?

[Carl Schwamberger]

Getting back to the OP

...

Did analysis later by the US indicate Tarawa could have been bypassed once the islands where aircraft sortied from to use its airfield were captured?

Or was the airfield regularly used by the US post-capture to warrant the attack even with the knowledge afterwards of the benefits of island hopping?

The post battle analysis might be partially summarized thus:


1. There had been very little experience in assaulting fortified beaches & small islands. Near all the previous beach assaults against the Japanese had been vs lightly defended beaches. The Japanese had preferred to defend inland around the critical objectives. The very few fortified islands similar to Betio were small company and battalion sized affairs. ie: the Marines attacks on Tulagi, Gavutu, and Tanambogo islands adjacent to Guadalcanal. Despite the extensive entrapments and bunkers the Marines managed to kill near all the 800+ defenders at a cost of 122 dead. Otherwise the battles vs well entrenched or fortified Japanese were conventional inland battles, such as the Umbrogol hills on Guadalcanal, or elsewhere in the Solomon islands. Post Op GALVANIC the Marines heavier up their assaults with more automatic weapons, heavy weapons on the LVT, more medium tanks vs light tanks, More engineer weapons like explosive charges and flame throwers.

2. Increasing robustness of communications. This was not just adding more radios. The break down in radio communications on the first day of the Betio battle was not new, and was not as bad as had occurred in other battles or in future beach assaults. One of the thing that went right and was built on was that when major radio circuits failed the leaders and operators were able to patch together alternate channels. Specifically Shoup was able to gain tactical coordination with the battalions of the adjacent regiment & substitute for the failure to establish a division forward tactical radio net. It was still a ugly mess but it got the job done and strongly reinforced earlier lessons on the need for depth and strong flexibility in using the radio channels and equipment.

3. Discarding Armor doctrine. The tactical doctrine taught the Marine tankers at the Army armor school was shown to be worthless in the context of assaulting prepared positions. Advancing deep into the enemy position ahead of the riflemen and "Circulating on the objective" resulted in the loss of too many of the tanks that made it ashore. Aside from retraining the tanks and rifle companies to operate as a single tactical unit the need for direct voice communications between each tank crew and the adjacent riflemen was seen. This led to the eventual placement of a intercom link outside the tank. The rear fender telephone.

4. Absolute priority to fire support during the assault. This connects directly to #2. Anything that gets in the way of directing and executing fire support for the assault has to ruthlessly set aside & the comm/execution proceed rapidly & unhindered. This was still a lesson with us in my training in the 1990s. Every radio or other comm device can be commandeered by the fire support, the NGF observers, artillery, FO, the air spotting team, and the operators/supervisors on the other end or whatever channel or network must understand the fire support messages and be able to forward them efficiently.

5. Improved intel analysis of the enemy ground defenses. The subsequent estimates in the marshals were not perfect, but better than those for Betio.

This list could be extended considerably with many details. One lesson learned but not imeadiatly acted on was provision of properly trained close air support to these island assaults. The Navy placed a low priority on embarking Marine bomber groups aboard carriers. The Navy pilots substituted were ernest and motivated, but a few weeks of training proved inadequate. The sort of CAS the Marines had developed previously became unavailable for near another year before the Navy decided it has aircraft carriers to spare for Marine air wings.

[Felix C]

Reading the small role planned for tanks on Tarawa and the tiny quantity provided and non-existent training to cooperate with infantry is surprising in view that this was late 1943 with tank-infantry cooperation already shown on Guadalcanal, New Georgia, North Africa, Sicily. The tanks which made it to shore were very effective.

Also strange to read it was implied armor piercing naval shells were not used on Betio and were later. I presumed naval gunfire was not effective at B. due to the level terrain making penetration difficult unless well offshore and using a plunging shell trajectory.

It does seem the other islands in the Marshalls attacked were not as well defended in terms of prepared fortifications compared to Betio. Have to wonder if the Japanese saw what was occurring in G. in late 1942 and elected to focus fortifying Betio in 1943 as that was the furthest point of their line and most likely open to attack.