Commanders, Organizations, and Strategies For The Pacific War


The two men who had the greatest impact on Pacific war strategy were Admiral Isoroku Yamamoto and Admiral Ernest King. Both were effectively in charge of their nation's naval operations when the war broke out between them. Both were "air-minded" and had commanded iconic aircraft carriers, Yamamoto the Akagi and King the USS Lexington. Both used their considerable influence to significantly change their nation's naval strategy away from long-held, pre-war positions. Both were regarded as smart, demanding, difficult to work with, and adept at using political maneuvering to get their way.

Admiral Isoroku Yamamoto

Admiral Yamamoto was Commander in Chief of the Combined Fleet, comprising Japan's five "mobile fleets" and three "area fleets." The five mobile fleets contained the principal warships. First Fleet ("Main Body") and Second Fleet ("Advanced force") contained battleships and cruisers respectively. Third Fleet, also referred to as the "Striking Force," held the aircraft carriers.

Yamamoto's immediate supervisor on paper was Admiral Osami Nagano, Chief of the Imperial Japanese Navy General Staff (IJN), which along with the Chief of the Imperial Japanese Army General Staff Office (IJA), reported to Imperial General Headquarters (IGH). In fact, Yamamoto was an extremely popular figure and, by threatening to quit, succeeded in getting his way even over Nagano's objections. He refused to be limited by the master war plan handed to him by IGH that embodied the long-standing IJN strategy of enticing an enemy's naval power to come to her. Instead, he insisted upon taking the war to the enemy with an initial strike on the American Navy at Pearl Harbor. Later, when his plans to invade Midway Island were opposed, he threatened to quit again. And again he got his way.

Although the original prewar strategy was not implemented, it determined the design and construction of ships, aircraft, and weapon systems with which Japan entered the war. Limited by treaties to having fewer capital ships than the US and UK, Japan's master plan was to neutralize their enemy's numerical advantage by gradual attrition as an enemy US fleet raced toward Japan upon the outbreak of hostilities. Based upon wide ranging surveillance, IJN submarines would be sent to sink or cripple ships. Land-based naval aircraft striking from Japan's Pacific Ocean islands would use bombs and torpedoes to sink or cripple more enemy ships. Then cruisers and destroyers using long-range torpedoes and night-fighting tactics would further weaken the approaching fleet. Carrier launched bombers and torpedo planes would continue the attrition. By the time the weakened enemy fleet finally engaged IJN in the ultimate, decisive battle, the odds would no longer be against Japan. Her battleships, protected by air cover from carrier-launched fighters, would prevail over those of the enemy. This scenario required that Japan be able to take the initiative through use of torpedoes, planes, submarines, and other warships with extended ranges and striking power. Design of ships and planes emphasized the offense at the expense of the defense. For aircraft carriers and carrier-launched aircraft, this translated into lighter, faster, longer range, and more punch but with less protection.

Yamamoto's subordinate, the innovative Admiral Shigeyoshi Inoue, commander of the Fourth Fleet ("South Seas Force"), also contributed significantly to altering IGH's war plan. He insisted that protecting IJN bases would require that fortified airfields be established is several locations. These included Lae, Salamaua and Port Morsby in New Guinea and Tulagi on Florida Island near Guadalcanal in the southern Solomons. This would permit shuttling the limited number of aircraft available from base to base to confront Allied moves as they developed.

Another Yamamoto subordinate, the cautious Admiral Chuichi Nagumo, became commander of the Third Fleet's 1st Air Fleet, also known as the "Mobile Force" or "Kido Butai." It was the powerful "Kido Butai" with its six large fleet carriers and massed airpower of 414 planes that attacked Pearl Harbor.

Yamamato, although an early advocate of naval aviation, typically monitored attacks from the Yamato, the world's largest battleship with unmatched 18-inch guns. He strongly believed that winning the war would result from a great "decisive battle," similar to the Battle of Tsushima against the Russian Navy in 1905. Such a battle would probably involve powerful gunships as well as carriers. Yamamoto constantly looked for opportunities to bring this battle about. This doctrine to support the decisive victory was well established in the IJN and guided design of aircraft carriers and aircraft as well as the training of their officers. It also resulted in holding back total commitment of the massed gunboat fleets, such as the First Fleet, in order for them to be available for that decisive battle. This pursuit of a decisive naval battle persisted after Yamamoto's death in April 1943. As the Allies continued to breach Japanese defensive barriers, this pursuit ran parallel with a strategy for inflicting heavy casualties at every Allied amphibious offensive to convince the Allies to negotiate for peace.

Admiral Earnest King

Admiral King was Chief of Naval Operations responsible for American operations both in the Atlantic and Pacific. In February 1942, he became one of the original members of the Joint Chiefs of Staff along with Admiral William D. Leahy, Army General George Marshall, and Army Air Force General Henry H. Arnold.

Like Yamamoto, King was not satisfied with the war plans handed to him. The old “War Plan Orange” provided for responding to an assault on the Philippines by immediately sending the Pacific Fleet to the rescue. It assumed troops on Luzon could hold on as USN warships raced across the ocean to engage and soundly defeat the enemy. The scenario was similar to the original Japanese plan except for who would be victorious in that "decisive battle." This strategy was not the plan when the war started, however, and was certainly not feasible after the loss of the Pacific Fleet's battleships to carrier aircraft at Pearl Harbor. The plan to thrust across the central Pacific was revived later, after the US surpassed Japan in the number of aircraft carriers available. The War Plan Rainbow 5 that was in effect when Pearl Harbor was attacked contemplated simultaneous war with Germany and Japan. This plan provided for concentrating on defeating Germany first and maintaining only a defensive posture in the Pacific. It was embraced by the American Joint Chiefs as well as by the British. Operations in the Pacific were to be restricted to protecting areas east of the 180th meridian, approximately the International Date Line, and would consequently concede many South Pacific islands to the Japanese.

King almost immediately began a political campaign to enlarge his mandate in the Pacific to include protecting the sea-lanes from America to Australia, "safeguarding vital interests," and seizing "vantage points" from which offensive operations could be launched. For this "passive defense" he needed ships, aircraft, and troops. His efforts were strenuously opposed by the Army Air Force that expected to achieve victory in Europe through strategic bombing and regarded bombers sent to the Pacific as wasted. The Army also opposed King, given General Eisenhower's priorities for ensuring that Britain and the Soviet Union remained able to fight and given General MacArthur's priorities for winning the Pacific war with himself in charge. The British also opposed King, being more concerned about their nation's immediate survival than about near-term operations in the Pacific.

Nonetheless, to protect shipping lanes and vital interests, King sent to the South Pacific fleet carriers USS Lexington in January 1942 and USS Yorktown the following month. The month after that, in early March, he presented his strategy to President Roosevelt and the Joint Chiefs to hold Hawaii, support Australia, and move northward from the Allied base in New Hebrides against the Japanese. He was limited, however, to the use only the current manpower commitments to the Pacific, then at 41,000 Army troops and 15,000 Marines. It is a reflection of Admiral King's aggressiveness, persistence, and effectiveness that, despite the "Europe First" priorities, almost all of the US troops sent overseas during the first six months of the war went to the Pacific and that the first American offensive of the war was at Guadalcanal rather than in North Africa.

In achieving this result, he was helped considerably by the planning of Richmond Kelly Turner, then Chief of War Plans Division and later commander of the amphibious force that invaded Guadalcanal. Reporting to Admiral King were both Admiral Chester Nimitz, Commander of the Pacific Ocean Areas and Admiral Robert Ghormley, Commander of the South Pacific Area. The Joint Chiefs appointed General MacArthur Commander of the South West Pacific Area.

Admiral Chester Nimitz

Admiral Chester Nimitz assumed command of the Pacific Fleet days after the attack on Pearl Harbor reduced the striking power of the US Pacific fleet by eight battleships. To him fell the task of translating Admiral King's aggressive plans for the Pacific into victories against a now superior, more experienced Japanese navy. Nimitz' quiet dignity and calm demeanor did not deter him from making bold decisions. He promptly ordered that the task forces centered on his three aircraft carriers begin raiding enemy bases. Throughout the war, Nimitz made wise command changes when needed, sustained his worthy subordinates at critical junctures, and provided the principles that governed strategic victories. Historian Toland credited Nimitz with making all the right decisions for the decisive Battle of Midway before a shot was fired.

Admirals Raymond Spruance and William Halsey

USN Admirals Raymond Spruance and William Halsey Jr. distinguished themselves early in the Pacific war, the former at Battle of Midway and the latter during the Guadalcanal campaign. Their many successes reflected strongly contrasting inclinations for aggressiveness, caution, and the balancing of immediate attack opportunities against responsibilities for successes of overall offensive and defensive objectives. Both were subjected to criticism for their command choices during the war, even as they achieved significant successes.

Spruance began the war subordinate to Halsey as commander of a cruiser division. His cruisers escorted Halsey's carriers during their early raids on Japanese-held islands in the western Pacific and during the Doolittle Raid on Tokyo. When commanding his task force during the USN defense of Midway, Spruance followed Admiral Nimitz's guidance regarding "calculated risk" using a mix of aggressive, all-out commitment when launching his first strike balanced with a cautious retirement behind Midway Island to protect the island and his fleet after sinking four first-line IJN carriers.

Some believed at the time that Spruance missed a significant opportunity to sink even more ships and should have pursued the "defeated" enemy fleet. In fact, Yamamoto was bringing forward his battleships and cruisers in hopes of a decisive night engagement against Spruance's carriers. Two years later during the Battle of the Philippine Sea, when covering USN landings in on Saipan in the Mariana Islands, Spruance's carrier aircraft and submarines sank three IJN carriers and virtually wiped out the Japanese naval aircraft capability for the rest of the war. Again some believed Spruance should have followed up immediately by pursuing the defeated and retreating enemy fleet, then comprising 90% of IJN's naval forces. Again, however, Spruance chose to defend the Allied landings at Saipan, which he perceived as his principal assignment from Nimitz, rather than to attempt to sink more ships.

Halsey was inclined to unrestrained aggressive action, even in the face of significant risks and restrictive operational orders. He once stated that, "As long as I have one plane and one pilot, I will stay on the offensive." This served America well during the Guadalcanal campaign, the most tenuous period of the Pacific war. While earlier commanders of the South Pacific Area were doubtful about the ability to sustain the US position on Guadalcanal, Halsey boldly committed his fleet, including his few carriers, to supporting the Marines there. This cost the USN many men, aircraft, and ships but, in the end, inflicted greater damage on the enemy and enabled the Americans to hold Guadalcanal. This marked the third major and decisive turning point in the Pacific war. Together with Marc Mitscher, another admiral heavily inclined to the offensive, they successfully fought their way up the Solomon Island chain.

Unrestrained offensive action, however, could have negative consequences as well as positive ones. The year after successfully clearing the Solomons, Halsey's aggressiveness was severely criticized after he pursued the then emasculated IJN carrier fleet far away from landings at Leyte Gulf in the Philippines. The IJN fleet, with carriers virtually stripped of aircraft after Spruance's "Great Marianas Turkey Shoot" in the Philippine Sea, was sent as a decoy to lure Halsey's powerful fleet away from other IJN forces so that the latter could successfully assault American landings at Leyte Gulf. Halsey took advantage of conflicting orders from Nimitz regarding his assigned priorities and took the bait, preferring to aggressively engage an enemy naval force and sink carriers than to provide support for an amphibious landing. He chased after the decoy fleet and succeeded in sinking four IJN carriers. In doing so, however, he left the Leyte landing dangerously exposed to IJN attack. Potential catastrophe for American forces at the Leyte landings was avoided in large part by the courage of a small, very much out-gunned USN fleet of escort carriers, destroyers, and destroyer escorts then under Gen. MacArthur's command off Samar. These escort carriers and their escorts fought so aggressively that the Japanese commander thought he was facing Halsey's main fleet and retreated. Over 1,500 USN servicemen died and five American ships sank during this battle, including two escort carriers.

Two months later, mindful of criticism leveled at him for not properly supporting the troops at Leyte, Halsey kept his fleet aggressively focused on supporting Gen. MacArthur's invasion of Mindoro, as promised, even in the face of his fleet's fighting for survival against a devastating typhoon. Halsey's orders to maintain formation and attempt refueling during this storm resulted in the loss of more servicemen, ships and about as many aircraft as were lost in combat during the battle of Midway. Again Halsey's judgment was questioned, and a formal inquiry was held. As in the case for Spruance, however, senior commanders and naval historians concluded that Halsey's "inherently bold leadership and strategic and tactical attack instincts" were, on balance, to his credit and to America's overall benefit. America needed war heroes and Halsey, like Gen. McArthur, was one to satisfy that need.

From August 1943 to the end of the war, command of the powerful, virtually unstoppable USN "Big Blue Fleet", which included America's Fast Carrier Task Force, alternated between Admirals Halsey and Spruance. It was designated as the Third Fleet, including carrier Task Force 38 when Halsey was in command and as the Fifth Fleet, including carrier Task Force 58, when Spruance was in command. While one of these commanders and his staff were attacking the enemy, the other commander and his staff were planning subsequent attacks. The timing of changes in command and some of their operations was as follows:

Admiral Chuichi Nagumo, Tamon Yamaguchi, and Jisaburo Ozawa

According to naval historians Jonathan Parshall and Anthony Tully, Admiral Nagumo was past his prime when he assumed command of IJN’s awesome Kido Butai. He did not grasp the complexities of aerial warfare and tended to be passive rather than innovative, the opposite of his commander, Admiral Yamamoto. He relied heavily on his chief of staff, Admiral Ryūnosuke Kusaka, for decisions. At Midway, according to historian John Toland, Yamamoto conceived the operation too recklessly and Nagumo fought it too carefully.

Admiral Tamon Yamaguchi, captain of the carrier Hiryu, was unlike and had little respect for his commander, Nagumo. He was aggressive, hot tempered, and the epitome of the traditional samurai. He went down with his ship at Midway.

Admiral Ozawa, Nagumo's replacement after the Battle of Santa Cruz Islands, was more air-minded but still reticent and deliberate. In 1941, he had been instrumental in the revolutionary development of the Kido Butai and regarded as one of IJN’s most capable flag officers. Unfortunately for him, his overall command encompassed the period of declining naval resources relative to the US and the resultant humiliating IJN defeats.

Bresnahan, Jim (2011). Refighting the Pacific War- An Alternative History of World War II. Annapolis, MD: Naval Institute Press.
Costello, John (1981), The Pacific War
Drury, Bob; Clavin, Tom (2007). Halsey's Typhoon. New York, NY: Grove Press.
Frank, Richard B. (1990). Guadalcanal- The Definitive Account of the Landmark Battle. New York, NY: Penguin Books USA.
Parshall, Jonathan; Tully, Anthony (2005). Shattered Sword. USA: Potomac Books.
Potter, E. B. (1985). Bull Halsey. Annapolis, MD: Naval Institute Press. p. 221.
Symonds, Craig L. (2011). The Battle of Midway. New York, NY: Oxford University Press.
Symonds, Craig L. (2018). World War II At Sea. New York, New York: Oxford University Press.
Toland, John (1970). The Rising Sun - The Decline and Fall of the Japanese Empire 1936-1945. New York, New York: Random House.

Last Major Update: Apr 2021

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Visitor Submitted Comments

1. Jim Schaefer says:
28 Apr 2021 06:40:51 AM

I am surprised that Admiral Nimitz is hardly mentioned in this article. He worked with King to shape USN strategy and very effectively commanded Spruance and Halsey while also guiding the development of the tools and resources for the USN's successes in the Pacific.
2. Bob Bryant says:
6 May 2021 10:54:15 AM

Thank you very much for your comment. I agree that Admiral Nimitz’ important contributions should have been included. The article has been updated to reflect that. I would welcome any additional thoughts you may have for improving the article.

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