1. NAVAL WAR COLLEGE
Newport, R.I.
Operational Art Exam
Evolution of the Operational Idea – from Midway to the Marianas & How
Functions and Factors interacted during Operation Forager
By
Ben L. Anderson
LCDR USN
A paper submitted to the faculty of the Naval War College in partial satisfaction of the
requirements of the Joint Military Operations Department course in Joint Maritime Operations.
The contents of this paper reflect my own personal views and are not necessarily endorsed by the
Naval War College or the Department of the Navy.
Date: 07 APR 2015
JMO 2015
LCDR Ben L. Anderson
Ben.Anderson@USNWC.edu
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Starting from the "date which will live in infamy," and ending on the decks of the USS
Missouri, the United States military dramatically changed. While some of the changes were
physical (the size and technology possessed), the predominant change was the development of
the art of warfare which led to the eventual defeat of the Japanese. From the lessons learned in
the Battle of Midway, through the "Marianas Turkey Shoot," our military leaders honed their
skills, learned from their mistakes, and improved through each encounter with the enemy. The
comparison between the operational idea behind the battle at Midway and Operation Forager
exhibits this change in maturity quite clearly. Further, by examining the way the United States
applied the operational functions of Intelligence and Fires to leverage the operational factors of
time, space and force in Operation Forager, the extent of this maturity is readily recognized.
This paper begins with a comparison of the elements of the operational idea behind the Battle
for Midway and Operation Forager. This is followed by a discussion of the operational functions
of Intelligence and Fires to include how they were leveraged in Operation Forager to shape the
inevitable Japanese response and leverage the operational factors of time, space and force.
When one discusses the concept of operational idea, the elements of an operational idea as
defined by Vego in one of his several books can be used. While Vego lists them slightly
differently in at least three of his books (Joint Operational Warfare - Theory and Practice,
Operational Warfare at Sea - Theory and Practice and Major Naval Operations (Newport Papers
#32)), they are very similar. For the case of this paper, the elements as discussed in Joint
Operational Warfare - Theory and Practice will be used. In the analysis and comparison of the
elements of the operational idea behind Operation Forager to that of the Battle of Midway, it is
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clearly evident only now how much the United States matured in its understanding of modern
naval warfare.
To see this maturity, it is essential to examine the objectives behind each battle and examine
how they shaped the decision making process. For Midway, the objective was simple - do not let
the Japanese establish a foothold. Midway was a defensive operation which was critical to ensure
that American combat power could be built up in the region, and to ensure that Hawaii remained
available to US forces. For Operation Forager - it was the culmination of the Campaign Plan
Granite. Admiral King stated there were four primary objectives in this endeavor: (1) interdict
the Japanese sea lines of communication, (2) secure basing facilities for long range air attack of
the Japanese mainland, (3) secure basing for naval operations which would be used for
penetration into Japanese home waters, and (4) isolate and neutralize the Japanese forces based
in the Carolines.
The first element to examine is that of the use of selected principles of war. In Operation
Forager and Spruance's reaction to the Japanese response (A-Go), Spruance leveraged the
concepts of objective, unity of command, unity of effort, and restraint. For the objective,
Spruance understood the strategic significance of the taking of Saipan, Tinian and Guam, and
how through that action, final victory over the Japanese would be enabled. It was for this reason
he was able to exercise restraint when urged to pursue a decisive battle with the Mobile Fleet,
choosing instead to ensure the safety of the landing force. Despite differing opinions by senior
officers within the Task Force, unity of command was maintained, thereby ensuring unity of
effort in achieving Spruance's goals. In the battle of Midway, Spruance also showed restraint,
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choosing not to press the advantage by pursuing his enemy at night - knowing that the Japanese
ships were not only more capable craft, but the crews were trained in night engagements.
Further, the principles of surprise and being on the offensive were leveraged at Midway contrary
to their lack of use in the Marianas. The ability to put the ships to sea, to maintain radio silence
to prevent detection, then the unquestionable good fortune of the Japanese submarines arriving
too late to their positions to detect them all allowed for the inferior and outnumbered force to
overcome the Japanese assault at Midway.
Operation Forager truly leveraged the element of sequencing and synchronization that were
completely absent at Midway. Where Midway was a reactive plan, developed in a relatively
short time period, to only ensure that the Japanese did not establish a foothold near Hawaii,
Operation Forager was a significant portion of Campaign GRANITE. Operation Forager used
sequencing to establish the order in which Saipan, Tinian and Guam would be attacked, and
synchronization when suppressing the land based aviation in Guam and preventing the Mobile
Force to obtain a safe haven for landing following their attacks on Spruance's Task Force.
Unlike the previous elements, the element of deception was essential to the success at Midway,
whereas it did not play a significant role in Forager. At Midway, with the deployment of a much
larger fleet than expected by the Japanese, combined with strict operational security, the
concentration of force the United States was able to muster completely surprised the Japanese.
At Midway, the United States neither had the power nor the time to effectively use operational
fires to achieve a significant effect, while in Operation Forager it played a critical role. Through
operational fires, the United States virtually shaped the Japanese force. This was done through
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the destruction of the majority of the Japanese's land based aviation, disruption of their sea lines
of communication (restricting the availability of refined oil for fuel), and the disruption to the
resupply and reinforcement efforts to Japanese garrisons already entrenched in the Marianas. The
use of tactical fires early in the Midway battle was unable to achieve an operational effect as the
effort was poorly coordinated, the targeting ineffective, and had it not been for bad decisions on
the Japanese side, most likely would have been disastrous for the United States.
The use of operational pauses was a vital improvement to the operational idea of Operation
Forager compared to Midway. Spruance, having learned from Midway the challenges of trying
to fight a battle while constrained by fuel, ensured not only were sufficient operational pauses
implemented in his plan, but moved them as necessary to leverage the operational tempo in his
favor. Additionally, the efficiency at refueling and resupplying at sea during these operational
pauses greatly increased combat potential of Spruance’s force.
In the element which discusses the protection of the friendly center of gravity, it is essential to
note what each commander had determined as their center of gravity (CoG). In the case of
Operation Forager, Spruance determined that his CoG was the landing force, and ensured that his
forces stayed within range to ensure their defense. This was similar to the effort by Nimitz at
Midway to ensure that the carriers remained relatively safe.
Comparatively to Midway, Spruance did not have a significant worry about the regeneration of
combat potential during Operation Forager. He outnumbered the Japanese significantly and had a
more technologically advanced and proficient fighting force than Admiral Ozawa and the
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Japanese mobile force. The only time Spruance needed to regenerate combat potential was prior
to the landing in Guam, due to unexpected and fierce resistance at Saipan. At Midway, while
Nimitz would have greatly appreciated the ability to regenerate combat potential, there were
insufficient forces available at that time to support him.
The use of branches and sequels was another facet used within Operation Forager which was
neither used nor required at Midway. At Midway the task was simple - not to let the Japanese
establish a foothold. In Operation Forager branches were used to allow for flexibility in the plan
to take advantage of the tactical situation (choice of beach landing areas based on established
Japanese defenses). Sequels were also used to provide for a concentration of force at each of the
tactical objectives (the choice to assault Saipan, then Guam, then Tinian).
At Midway, Nimitz assessed that the carrier force of the Japanese was their CoG, and made
every effort to target those ships before anything else. Interestingly enough, Yamamoto at this
point believed that his battleships were his CoG. In the battle with the Japanese in the Philippine
Sea, Spruance also assessed that the Japanese carriers were the CoG of the Japanese, but chose
not to focus his effort in attacking them directly, but to defeat the Japanese air forces as they
attacked, remaining in position to cover his own operational CoG - the landing force.
This brings into the assessment how in each battle the method for defeating the enemy CoG was
implemented. In Midway, it was through sheer tenacity and luck (and bad decisions on the
Japanese's part) that the United States was able to defeat the Japanese through inflicting
sufficient damage on the Japanese carrier force. In the Philippine Sea - it was through the almost
total destruction of the Japanese air forces alone that victory was achieved.
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The final element to be examined is that of the use of operational reserve. In the case of
Midway, there was not much depth to the bench for the United States. Virtually all the force that
could be mustered was utilized in the battle. In the Philippine Sea, there was never a need for an
operational reserve when confronting the Mobile Force. While the engagements were so one-
sided, the need for an operational reserve didn't exist, but in fact did - as Spruance had sufficient
forces spread out to ensure the protection of the landing force, they could be called upon if
needed. An operational reserve did exist for the landing force, and upon disembarking them onto
Saipan, Spruance felt that he then could pursue the Japanese fleet.
There were many differences between the operational idea of the Battle of Midway and that of
Operation Forager. These differences were based on the new maturity of understanding in
modern naval warfare, and on the technological and numerical superiority of US forces. With a
solid understanding of the elements of the operational idea behind Operation Forager in hand,
one can now examine how the operational functions of intelligence and fires were leveraged by
the United States to shape the operational factors of space, time and force to its own advantage.
The use of intelligence played a crucial role in this shaping of the operational factors during
Operation Forager. First, despite the vastness of the space involved in conflict, both human
intelligence (HUMINT) and communications intelligence (COMINT) were leveraged to
effectively shrink the battlespace. Using HUMINT acquired from Philippine workers, the United
States was able to keep track of much of the Japanese fleet. Then, through the use of both
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submarines and radio direction finding stations scattered throughout the Pacific allowed for the
tracking of the Japanese fleet throughout the area.
COMINT was also leveraged to understand the Japanese force structure. Through the breaking
of Japanese codes and the intercept of their classified messages, the United States had a
considerable understanding of their composition and capabilities. This plethora of information
did however, lead Spruance to the wrong conclusion that the Japanese would attempt to conduct
an "end-run" on the landing force. This conclusion is the reason Spruance did not aggressively
pursue the Japanese fleet at the onset of the battle, as Spruance was determined to protect his
operational CoG (the landing force) from an "end-run" attack.
The use of radar for early warning played a vital role in the factors of both time and force.
Through the early identification of inbound enemy aircraft, which allowed sufficient time to get
defensive aircraft aloft, to the radar guided coordinated attack by our own forces (which
essentially acted as a force multiplier), radar was invaluable to Spruance and his fleet.
Aside from the use of intelligence, the use of fires also played a vital role in the shaping of the
factor of force.
From the cumulative effects of the previous operations of campaign plan GRANITE, to the
continued action by Admiral Lockwood and the submarine force, the Japanese forces Spruance
faced in the Philippine Sea were the product of American action. First, the indirect fires against
Japanese shipping and oil supplies had forced the Japanese to be very conservative on their use
of fuel - preventing much of the training they needed from occurring. Further, it forced the
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Japanese to resort to the use of crude oil, which was inherently more dangerous to use due to the
high sulfur content. Second, the sustained effort from January through May of 1944 to disable
the land-based air assets, bases, strong points and shipping in the region denied the Japanese
crucial forces which had been previously relied upon in their Z-Plan.
Finally, in the last months leading up to the invasion of Saipan, the constant attrition of forces
and supplies the Japanese attempted to deliver to the islands played a substantial role in
mitigating the defensive capabilities of the garrisoned forces.
While the use of intelligence and fires played a role in shaping the operational factors, they
obviously could not shape them perfectly to Spruance's needs. Despite not being able to shape
them perfectly, the United States exploited each of the factors of space, time and force, as
thoroughly as possible to ensure their victory over the Japanese.
The operational factor of space had several key elements which need to be examined to
understand its effect in the overall war effort. First, the geographically strategic position of the
Marianas was crucial to the overall war effort. This position, as stated in the discussion of the
objectives above, would play a vital role in the effort to force the unconditional surrender of
Japan through providing basing from which both long range bombers and naval forces would be
able to assault the Japanese mainland.
While the operating space was effectively shrunk by the use of intelligence, it was still a vast
space which itself presented challenges to Spruance and his task force. Due to the openness of
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the area, the Japanese had ample open ocean in which they could maneuver, which made it
challenging to find them between radio intercepts and submarine detections. The Japanese also
had a longer operational reach due to the aircraft design, which allowed for them to place their
CoG outside the reach of Spruance's carrier based aviation. Further, while the Japanese were free
to maneuver, Spruance effectively tethered himself to the landing forces to ensure the safety of
his operational CoG.
One area in which the vastness of the battlespace was to the benefit of Spruance was facilitated
by the decision of Ozawa to place his Force "C" 100 miles ahead of his carrier group -
effectively removing any ASW protection. This later facilitated the attack and sinking of two
vessels in Ozawa's fleet.
Another key element which shaped the battlespace was that of the weather. The direction of
winds were to the advantage of the Japanese, allowing them to drive towards Spruance's TF
while launching and recovering aircraft. Spruance, on the other hand, had to burn fuel and
constantly reposition to ensure sufficient wind across the deck.
Unlike the factor of space which did not provide either side a definitive advantage, the factor of
time was vastly in favor of the United States. From the initial planning of Campaign GRANITE,
to the expedited schedule set into motion due to concerns about typhoon season, the United
States had the advantage and momentum. The Japanese had to abandon their Z-plan as they did
not have sufficient time to prepare in light of the accelerated pace the United States was moving
through the Pacific. The Japanese were denied the training time desperately needed to train their
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pilots and their new ship commanders to acquire the combat skills their plans relied on. This
increased operational tempo (along with the use of operational fires) denied the Japanese time to
reinforce their garrisons, complete their runways, and build up supplies to provide for their
desired decisive battle.
Time was both a positive and negative factor in tactical operations. As a positive factor, due to
the attrition rate of Japanese forces, time was of great benefit, as the Japanese culminated
quickly. Conversely, time limited American flight operations due to the lack of proficiency at
night landings. Finally, as discussed above - the use of improved radar allowed sufficient time to
launch aircraft on detection of Japanese assault waves.
At the time of Operation Forager, the United States had both the technological and numerical
edge over the forces the Japanese could muster. Spruance's task force maintained substantial
defensive combat power due to the experience of pilots, superiority of aircraft, communication
abilities and use of radar for both detection and coordination of attack against enemy aircraft.
This was further enhanced through outstanding combat discipline. The teamwork exhibited by
the pilots in the response to the waves of assaults aided in battle becoming known as "The
Marianas Turkey shoot."
Spruance’s force contained substantial inherent defensive combat power due to the experience
of pilots, superiority of aircraft, communication abilities and advanced use of radar. As to the
experience of the pilots, the United States’ paradigm for pilot training was demonstrated yet
again as extremely advantageous. All of the US pilots had significantly more experience than the
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Japanese counterparts. This experience combined with the technological innovations for anti-air
defense batteries and radar systems allowed for a much higher latent combat power than the
Japanese. The combat power was able to be maintained through ensuring the recovery of
downed pilots (which provided a significant long term advantage) and the efficiency and
proficiency of the refueling at sea capabilities of the fleet.
Operational leadership of Spruance - while sometimes questioned - was outstanding. His focus
remained the strategic goal of taking Saipan vice being lured into a possible trap by the Japanese,
despite arguments from his team. Further, Spruance prioritized actions to ensure the long-term
success of the campaign through actions such as the recovery of downed pilots.
In examining the interaction between the operational factors, a space-force relationship can be
seen in the way forces were employed in response to the Mobile Force attack. The landing force
was occupied on Saipan, along with a protective task force, while the bulk of Spruance's forces
engaged the waves of incoming aerial waves while simultaneously striking the Japanese facilities
on Guam. The space-time interaction was evident on the decision to adjust GRANITE's timeline,
to ensure that most of the action in the Marianas would be complete prior to the start of typhoon
season (July). The time-force relation can be seen through the delay to assault Tinian and Guam
due to the strong defense presented at Saipan.
It was clearly through a detailed comprehension of the operational factors of space, time and
force that the United States was able to conduct such massive and complicated operations in the
Pacific in 1944. Leveraging the inherent understanding of these operational factors and using
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some of the operational functions with a ruthless efficiency, the United States was able to shape
the battlefield by not only effectively deciding when and where to fight, but what the Japanese
were going to be able to fight with. This would not have been possible had it not been for the
maturity in operational art which developed over the course of the war. From the infant stages of
operational art as expressed by the operational idea at the battle of Midway, to the efficiency and
solidity of the operational idea behind operation Forager, the world saw that the United States
was a mature, professional, fighting force.
