The largest amphibious assault in history, Normandy, employed only brief and perfunctory pre-assault bombardment that was intended only to suppress the defenses, not destroy them. (2) Contrast that to the Pacific assaults on Iwo Jima and Okinawa where the Navy conducted non-stop bombardments for weeks prior to the actual assault. There you have the two extremes – nearly none and almost unlimited. Which philosophy is right? They can’t both be right, can they? Let’s look a bit closer at the historical basis for the two different philosophies and, with that understanding, try to assess our current naval bombardment needs, if any.
As noted by historian and former naval amphibious planner, Christopher Yung, in his book “Gators of Neptune (1), which documented the naval amphibious planning for Normandy,
Another point of departure with Pacific amphibious doctrine was the Mediterranean view of the purpose, effectiveness, and duration of a naval bombardment of coastal defenses just before an amphibious assault. Admiral Cunningham [Command in Chief, Mediterranean Fleet, First Sea Lord] … stated that, “the Americans in the Pacific placed a high value on naval bombardment in support of amphibious assaults, particularly by battleships, much higher than I thought was really justifiable.” (1, p.38)
However, Yung further notes that Admiral Cunningham changed his mind.
Following the war, Cunningham felt he should have given greater credence to the value of naval gunfire support for an amphibious landing … (1, p.38)
Based on their experience with various Mediterranean assaults, the US Army believed that pre-assault bombardment served only to alert the enemy and ruin the element of surprise. (1, p.38) The Royal Navy’s RAdm. L.E.H. Maund seconded this philosophy but ascribed it to the British military’s deficient resources. (1, p.39) We see in this thinking the belief, potentially correct, that if the attackers have less than overwhelming force that the element of surprise may be more important than pre-assault destruction. Of course, one could ask why anyone would attempt an amphibious assault with less than overwhelming force but that’s a separate issue.
Supporting this minimal bombardment belief was British data on artillery effectiveness against hardened defenses which led the British to conclude that naval gunfire could, at best, provide suppressing fire which might temporarily neutralize the defenses but would be ineffective at destroying them. (1, p.39) It should be noted, however, that there is a world of difference between artillery fire and very larger caliber battleship and heavy cruiser fire with up to 16” guns. The British did not appear to take that difference into consideration.
Yung notes, however, that this ‘Mediterranean’ minimal bombardment philosophy was not unanimous. VAdm. Hewitt (commander US naval forces, Mediterranean) noted that pre-assault bombardment was an essential precursor for a successful assault. (1, p.39)
It is also noteworthy that the Mediterranean philosophy was derived from early war experience with less accurate and less lethal artillery and naval guns. As the war went on, naval gunfire accuracy and lethality improved immensely
Eisenhower, himself, weighed in on the value of naval bombardment, stating that,
Pre-assault and support naval gunfire on beach defenses and pre-arranged targets was so devastating in its effectiveness as to dispose finally of any doubts that naval guns are suitable for shore bombardment. (1, p.39)
His thoughts did not, however, wind up dictating the extent of the Normandy pre-assault bombardment which was, by Pacific standards, minimal, at best.
RAdm. Hall (Commander, 11th PHIBFOR, Force Omaha), expressed his dissatisfaction with the pre-assault bombardment after the Normandy operation was over.
It is believed that the time available for pre-landing bombardment was not sufficient. German defensive positions were well camouflaged and strong. It is considered that these positions should be destroyed by slow aimed fire from close range prior to the landing. Something more than temporary neutralization is required when troops face beach mines, wire, anti-tank ditches and similar obstacles after landing. (1, p.208)
Note Hall’s call for close range naval fire (enhanced accuracy) as opposed to standoff fire (reduced accuracy). As it happened, there were instances of individual destroyer Captains, on their own initiative and in violation of planning, moving their ships very close in to provide effective and critical point-blank gunfire. This illustrates the element of risk in effective naval bombardment and the acceptance of that risk in order to achieve objectives. Contrast this with today’s exceedingly risk averse Navy culture!
In contrast to Hall’s deprecating view of the bombardment effort, Adm. Ramsay (Allied Naval Commander, Expeditionary Force) thought the minimal pre-bombardment was adequate and justified.
That naval gunfire neutralizes rather than destroys is still considered to be true … the policy of beach drenching [ed. short term suppressive fire] has been fully justified. (1, p.208)
Ramsay, then, believed it preferable to momentarily neutralize (suppress) enemy defenses rather than put any great effort into destroying them.
In the actual event, post-assault observation and analysis indicated that relatively few fortifications, gun housings, and casemates were outright destroyed. This should come as no surprise given the inaccuracy of fire control at that time and the minimal amount of time the bombardments were conducted. Pacific experience differed greatly.
The use of high velocity guns at [Kwajalein] showed, at least according to the US Navy, that this weaponry could be effective at smashing concrete pillboxes. (1, p.77)
As the Army noted, pre-assault bombardment does, indeed, notify the enemy of the coming assault. At that point, it becomes a race between the attackers getting sufficient force ashore to achieve their objectives and the defenders getting sufficient reinforcements to the area to ward off the assault. For Normandy, where the potential pool of reinforcement was vast, it was feared that a prolonged pre-assault bombardment might have allowed the Germans time to reinforce beyond the point that the assault force could overcome. In contrast, in the Pacific, the Japanese forces on a given island had no source of reinforcement. Hence, losing the element of surprise was irrelevant – the defenders couldn’t reinforce and couldn’t leave. They were fixed and isolated and every additional hour of bombardment meant fewer and less effective defenders and defenses.
While the concept of minimizing pre-assault bombardment in order to minimize the enemy’s time for reaction and reinforcement has some surface appeal and, indeed, logic behind it, the larger driving force of overwhelming force ought to negate the concept. If one has overwhelming force (and if you don’t, why are you attempting the assault?) then the enemy’s reinforcement efforts can be interdicted with air power, airborne infantry, and long range battleship gunfire. This presents the best of all worlds: extensive pre-assault bombardment reduces the immediate enemy defenses and the overwhelming force interdicts the reinforcement effort. Thus, both the immediate defenses and the reinforcements are attrited before the actual landing occurs. To a large extent, interdiction of reinforcements actually occurred at Normandy, thanks to overwhelming force, although the interdiction was divorced from an extensive pre-assault bombardment.
The British view that the element of surprise was necessary to make up for a lack of resources – meaning, a less than overwhelming assault force – was not an issue for the Americans in the Pacific as every US assault did involve overwhelming force. Thus, surprise was, again, irrelevant.
In contrast to the Mediterranean view that bombardment was ineffective at destroying defenses, Pacific bombardments did achieve the objective of forcing the Japanese to concede the actual landing and retreat to inland prepared defenses in the form of caves, tunnels, and other fortifications that could be hidden from easy observation and protected from heavy bombardment. Shore defenses were, in fact, found to be susceptible to prolonged bombardment, hence, the relocation of the defending assets to inland locations.
From the preceding discussion we see, then, the tension between the two conflicting philosophies:
- The desire to maintain the element of surprise
- The desire to inflict as much pre-assault destruction on the enemy as possible
While both philosophies offer seemingly valid arguments and rationales, it appears that the Mediterranean philosophy of minimal bombardment is largely based on assault force shortcomings and failings such as the lack of overwhelming force, limited resources, and doctrinally ineffective application of naval gunfire. Thus, for a properly resourced amphibious assault the Pacific practice of prolonged pre-bombardment would appear to be the correct choice.
Having examined the issue of pre-assault bombardment, it is important to note that the discussion has nothing to do with bombardment support during and immediately after the assault landing. Regardless of whether the assault used minimal or maximum pre-assault bombardment there is an undisputed need for naval gun support during the actual landing and immediately after, until the landing force can get their own artillery ashore and operating.
How does all this impact our views on naval gunfire today? As you might expect, the exact same considerations and conclusions about pre-assault bombardment still apply. However, technology has introduced some modifications into the methodology:
Range – Today’s defenders can use cruise and ballistic missiles with ranges of hundreds or thousands of miles. Even modern artillery and rocket launchers have ranges of many dozens of miles. Thus, bombardment must not be limited to the immediate landing area but must take into account defending ‘batteries’ located hundreds of miles away. These remote targets may need to be serviced by air power rather than naval guns but, regardless, they must be accounted for.
Interestingly, the potential remote range of defenses might, in some cases, mean that there are relatively fewer defenses/defenders at the actual landing site as compared to the WWII scenarios of highly concentrated, localized defenses and defenders. If this is the case, the need for local bombardment may be reduced.
The effect of range, then, results in a modification of the definition of bombardment to include not just naval guns but also missiles and aircraft/bombs.
Interdiction – The ability to defend from hundreds or thousands of miles away means that the concept of interdiction has to be greatly expanded. Interdiction may have to occur hundreds or thousands of miles away. This also leads to the possibility that there may be no interdiction in the strictest sense of the word since the enemy may have no need to physically move reinforcements to the landing site. Still, there will almost certainly be some movement of enemy defenses toward the assault site and that movement, however far away, must be interdicted.
Precision Guidance – Many observers mistakenly believe that massive bombardments are no longer necessary thanks to precision guidance. However, the reality is that precision guidance is a very limited capability in a peer defended assault scenario.
For example, laser guided rounds are useless in bombardment because there will be no assets available to laser designate. In a peer defended assault scenario, aircraft laser designators will be unable to loiter over the battlefield providing target designation and ground forces won’t even be available until well after the initial landing and will be too busy surviving to calmly and casually laser spot targets. Further, the ground forces will be too localized and ‘compacted’ to designate targets more than a hundred feet in front of them even if they were willing to lift their heads above cover long enough to do so.
Ships can, if so equipped, provide their own laser designation but that would be valid only for visible, line of sight targets and a smart enemy is not going to provide many of those.
GPS guided rounds would be effective but only against known, fixed, visible targets. The reality is that a smart enemy will not provide many fixed, visible targets.
The reality is that unguided area bombardment is the only generally effective method.
- For a properly resourced amphibious assault, prolonged and heavy pre-assault bombardment is clearly the preferred action and is essential to ensure a successful landing.
- Post-assault gun support is always required.
- In order for bombardment to be effective and worth the effort, naval gunfire must employ large caliber, heavy guns of 8” or greater size. As demonstrated by WWII experience, 5” guns simply don’t have the power to effectively destroy hardened fortifications.
- The area of bombardment on today’s battlefield will likely have to be greatly expanded although the bombardment may take the form of aircraft or missiles in order to achieve the required range.
- Precision guidance is only marginally useful in an amphibious assault. Old fashioned area bombardment is still required.
Today’s US Navy utterly lacks the capability to provide amphibious pre-assault bombardment or supporting fires during the landing. If we continue to insist that we want and have this capability, we need to procure bombardment capability. The Marines long ago gave up their battleship gun support in exchange for a handful of magic beans and promises by the Navy that never came to fruition and they are now left with no naval gun support, whatsoever.
(1)“Gators of Neptune”, Christopher Yung, Naval Institute Press, Annapolis, Maryland, 2006, ISBN 1-59114-997-5
(2)Ibid. p.80-81,From the Overlord Outline Plan: “As preliminary bombardment compromises surprise, it should be confined to the shortest possible duration consistent with the achievement of the required degree of neutralization.”