Amphibious Assault Perspective

We often discuss the Marine Corps and amphibious assaults while noting that the Navy/Marines are currently unable to even implement an assault that would adhere to their own doctrine.  This is true enough, however, I suspect that part of our dismay about the Marine’s assault shortcomings lies in unrealistic expectations.  Too many of us, I think, envision the Normandy D-Day assault and use it as the basis of comparison.

Recall, though, that D-Day involved the best efforts of multiple nations, required years to build up the forces and equipment, and required the invention of multiple, specialized equipment (Hobart’s Funnies, for example, and the Landing Ship Tank, LST).  The ability to conduct D-Day was not a capability that we entered the war with.  We may have, debatably, had the germ of the concept prior to the war but it took wartime experience to refine and much effort to assemble and develop the necessary force.

We also need to firmly keep in mind that D-Day was the ultimate amphibious assault of all time in terms of scope.  We should not be comparing the Marine’s current capabilities to the D-Day assault and expecting the Marines to be able to conduct another D-Day at a moment’s notice.

Rather than looking at the D-Day assault, let’s look at a much smaller assault, Tarawa (Gilbert Islands), which occurred early in the Pacific Island campaign.  Despite being a smaller assault, the assembly of forces was still substantial.

The American invasion force to the Gilberts was the largest yet assembled for a single operation in the Pacific, consisting of 17 aircraft carriers(6 CVs, 5 CVLs, and 6 CVEs), 12 battleships, 8 heavy cruisers, 4 light cruisers, 66 destroyers, and 36 transport ships. On board the transports was the 2nd Marine Division and a part of the Army's 27th Infantry Division, for a total of about 35,000 troops. (1)

A small portion of the forces were assigned to seize Makin Atoll.  The naval force directly assigned to Tarawa included, (2)

Fleet Carriers             6

Light Carriers             5
Escort Carriers            5
Battleships                8
Heavy Cruisers             5
Light Cruisers             2
AA Cruisers                3
Destroyers                43
Minesweepers               2
Transports/Landing Ships  18

The ground force counted 35,000 troops.  By comparison, a Marine Expeditionary Force (MEF) consists of a Ground Combat Element of 18,000 troops and an Air Combat Element. (3)

While it is more appropriate to ask whether the Marines can, currently, conduct a Tarawa size assault we should note that the pre-WWII Marine Corps and Navy were not capable of that either.  They needed time to build up to that level.

Okay, so if we can’t fairly expect the Marines to be capable of even a Tarawa size assault on day one of a war, what is it that we do expect the Marines to be capable of?  Honestly, I don’t expect the Marines to be capable of anything on day one.  What I do expect is for the Marines to develop and maintain the institutional memory and knowledge of two main tasks:

Amphibious Core

Arguably, the Marine’s main responsibility is to keep the institutional memory of how to conduct amphibious assaults alive.  Unfortunately, a decade or more of land combat has largely allowed that memory to fade from existence.  Indeed, in recent years the Marines have begun conducting amphibious assault training exercises, to some limited degree, and have publicly expressed the need to “re-learn” how to conduct such assaults which, of course, means that they have forgotten how.  The institutional memory is gone.  This is tragic and will cost lives somewhere down the road when we have to re-learn the lessons in combat.  Allowing the institutional memory to be lost is unforgivable and many Marine leaders, current and recently retired, should live with the shame of that failing.

Setting aside blame, what is required from the Marines is to maintain and exercise a core of amphibious capability and knowledge which can be used to build a much more extensive wartime capability if/when needed.

This also suggests that maintaining a peacetime amphibious fleet of 33 ships or so is unnecessary.  If all the Marines need to do is to maintain the institutional memory, that can be accomplished with just 6-9 amphibious ships – basically, just a few ships conducting training exercises (institutional memory) or undergoing maintenance.  When war comes, we can build more amphibious ships, if needed.  This, in turn, suggests that we need a far more basic, cheaper amphibious ship design that we can build quickly during war.  A modified commercial ship is adequate for troop and cargo transport.  Our current big deck aviation/amphibious ships are far too large and far too expensive for rapid wartime construction.

Port Seizure

A subset of general amphibious capability is port seizure and it is this which I consider to be the Marine Corps’ main mission.  We’ve discussed the challenges presented by an over-the-beach amphibious assault and noted that the logistics, in particular, are currently unlikely, bordering on impossible.  With that in mind, the only way to currently insert a large force into a hostile area is via a port.  Only ships can transport the required mass of materiel and ships must have a functioning port.  The fantasy of moving an entire invasion force and all its follow on materiel through Mobile Landing Platform (MLP or whatever the Navy’s label of the day is) ‘sea bases’ is just that, a fantasy.  We’ll need a port and if a nearby, friendly port is not available then we’ll have to seize one.  That, after all, was the immediate objective of the Normandy D-Day assault – to seize the ports of Cherbourg and Le Havre through which would pour the millions of tons of subsequent supplies for the assault on Germany.

As with general amphibious assault, I don’t expect the Marines to have everything they need to conduct a major port seizure on day one of a war.  What I do expect is for the Marines to have the institutional knowledge about how to conduct a port seizure along with detailed plans and equipment lists that can be realistically and readily implemented when war comes.

Conclusion

Unfortunately, the Marines have lost the institutional memory of how to conduct general amphibious assaults and they never had any knowledge about port seizure.  Peacetime is the golden opportunity to practice these capabilities and develop the required institutional knowledge.  Unfortunately, the Marines are practicing neither capability.  The occasional, extremely limited, small amphibious exercises the Marines do conduct are so unrealistic as to be worse than worthless – worse, because they develop bad habits and false confidence.

In summary, I don’t fault the Marines for not being able to conduct a D-Day or Tarawa assault on day one of a war but I do fault them for not knowing how and not having detailed plans and equipment acquisition lists ready to go.  With this in mind, we can see that day one capabilities are a red herring.  What’s more important is ‘day two’ capabilities after you’ve had a chance to build up.

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(1)Wikipedia, “Battle of Tarawa”,  retrieved 28-Aug-2018,

https://en.wikipedia.org/wiki/Battle_of_Tarawa#American_order_of_battle

(2)Wikipedia, “Gilbert Islands Naval Order of Battle”,  retrieved 28-Aug-2018,

https://en.wikipedia.org/wiki/Gilbert_Islands_Naval_Order_of_Battle#TF_53_Southern_Attack_Force_(Tarawa)

(3)Global Security website, note – the table of data is not completely current but serves as an indicator,

https://www.globalsecurity.org/military/agency/usmc/mef.htm