D-Day Lessons

ComNavOps is currently reading the book, D-Day June 6, 1944: The Climatic Batle of World War II, by Stephen Ambrose.  The book is quite extensive at over 600 pages and is more of an oral history than a pure academic study, however, there are strategic and tactical lessons packed in throughout the book if one reads between the lines and can do a bit of self-assembly of the events and lessons.

Here  are some tidbits from the book that offer lessons relevant to today’s amphibious assault concerns.

Discussing the concept of defense of the western European coast from the anticipated Allied amphibious invasion, Field Marshal von Rundstedt, Western European Commander, argued against dependence on fixed fortifications.

“He argued that the Germans should hold their armored units well back from the coast, out of range of Allied naval gunfire, capable of mounting a genuine counteroffensive.”

This was a potentially devastating strategy that the Germans failed to implement thanks in large measure to Hitler and Rommel's personal obsession with fortification defenses.  This strategy offers a warning to us, today.  A peer defender will, undoubtedly hold back reserves and we must be prepared to deal with them.  Simply winning a foothold on the beach (or inland location in the case of vertical assault) is not enough.  Just as there will be defense in depth, so too must there be the ability to apply offense in depth. We must be prepared to attack not only the immediate assault site but the defender’s depth as well.

Not only will defenders withhold troops and armor from the immediate assault point but the existence, today, of long range rockets and missiles adds an additional element of defense in depth.  Given the extreme range of today’s missiles, we must be prepared to extend the assault for hundreds of miles – no easy task.

The importance of combat engineers is emphasized.

“Almost one-quarter of the American troops going in on the morning of D-Day would be engineers.  Their tasks, more less in this order, were to: demolish beach obstacles, blow up mines on the beach, erect signs to guide incoming landing craft through cleared channels, set up panels to bring in the troops and equipment (the color of the panel told the ships offshore which supplies to send in), clear access roads from the beach, blow gaps in the antitank wall, establish supply dumps, and act as beachmasters (traffic cops).”

Contrast this to today’s lack of emphasis on engineering tasks and the lack of specialized equipment for the engineering tasks.  Among other needs, the US desperately needs a modern, specialized Combat Engineering Vehicle (CEV).

The debilitating effects of sea-sickness are pointed out.

“Bingham [Maj. Sidney Bingham, CO, 2^nd Battalion, 116^th] did an analysis of what went wrong for the first and second waves.  Among other factors, he said, the men were in the Higgins boats far too long.  ‘Seasickness occasioned by the three or four hours in LCVPs played havoc with an idealism that may have been present.  It markedly decreased the combat effectiveness of the command.”

Consider that time frame of 3-4 hours rendering troops significantly less combat effective and then consider the Navy/Marine’s desire to move the assault starting point out to 25-50 miles with the resultant possible increase in transit times.  Yes, an LCAC can travel at high speeds but LCACs are not doctrinally considered as initial assault transports.  At the moment, we only have AAVs.  Various ideas have been put forth for dealing with the extended transit but none have yet been adopted.  Transport to the beach is a serious shortcoming today.

Mobility, on both sides, is discussed.

“Once in France, the Allied paratroops and seaborne troops would be relatively immobile.  Until the beachhead had been expanded to allow self-propelled artillery and trucks to come ashore, movement would be by legs rather than half-tracks or tires.  The Germans, meanwhile, could move to the sound of the guns by road and rail – and by spring 1944 they would have fifty infantry and eleven armored divisions in France.”

This is a potentially profound lesson for today’s proponents of aviation vertical assaults.  Once on the ground, the troops have little mobility and become, in essence, a fixed target.  The enemy can move large amounts of troops (and armor!) to the attack point fairly quickly.  An aviation assault, with its utter lack of armored vehicles must succeed in its mission quickly or risk being overwhelmed by responding enemy troops.  Further, additional support to interdict enemy troop movements by road or rail is mandatory, requiring that the aviation assault be much larger in scope than the mere assault element, itself.  How to provide that additional support at a, presumably, far inland location is a question not answered by current doctrine.

It was recognized that the initial assault was not the only or even the biggest challenge.  Sustainment of the assault was vital and problematic.

“So the Allies really had two problems – getting ashore, and winning the battle of the buildup.”

As we’ve discussed, sustainment of an assault is the real challenge and is a real shortcoming for US amphibious forces today.  We lack the numbers and types of transports and connectors to sustain a major amphibious assault.

The logistics of moving troops from ship to shore was the major impediment to the assault.

“… the chief limiting factor in planning the invasion was lack of sufficient landing ships and craft.  Indeed, that was the single most important factor in shaping the whole strategy of the war, in the Pacific, in the Mediterranean, in the Atlantic.  Churchill complained with some bitterness that ‘the destinies of two great empires … seemed to be tied up in some goddamned things called LSTs.’”

In a similar vein, General Eisenhower is quoted in the book as crediting the Higgins boat with winning the war.

“If Higgins (the inventor) had not designed and built those LCVPs, we never could have landed over an open beach.  The whole strategy of the war would have been different.”

The US has allowed its fleet of LSTs and other such vessels to nearly vanish.  We lack the means to get a sufficient number of troops and, more importantly, armor and artillery ashore in a useful time frame to say nothing of the follow on (sustainment) munitions, food, fuel, etc.

We see, then, that the historical example of D-Day offers many lessons that are still relevant today.  Yes, technology may have altered a few of the lessons but the alterations are more a matter of degree than obsolescence. 

I’ll offer a few more posts of this nature based on this book.  D-Day and its lessons are too important to leave in the dustbin of history.