The nine "Principles of War" were codified in the early twentieth century by British Major John Fuller. Good battle commanders had always understood and applied these 'well-known' fundamental principles long before they were ever written down. The principles are: Objective, Offensive, Simplicity, Unity of Command, Mass, Economy of Forces, Maneuver, Surprise, and Security. Foremost among them is the "Principle of the Objective". As stated in the official US Army Field Manual:
"Every military operation must be directed toward a decisive, obtainable objective. The destruction of the enemy's armed forces and his will to fight is the ultimate military objective of war. The objective of each operation must contribute to this ultimate objective. Secondary objectives of any operation must contribute to the attainment of the principal objective".
Simply stated, the commander must know why he's here on the battlefield, and know what he is expected to accomplish.
Nagumo didn't have the confidence of his superior officer, Fleet Admiral Isoroku Yamamoto. Yamamoto was disappointed in Nagumo's handling of the Pearl Harbor attack, which was only reluctantly and grudgingly embraced by Nagumo. Nagumo was not well grounded in air-sea operations, but since he was the senior officer in the Navy he became, ironically, the commander of the largest and finest air-sea attack force in history up to that time. His lack of skill was overshadowed by his extensive, though easy, victories over the American Fleet at Pearl Harbor and the British Fleet off Ceylon. Such success is hard to argue with, however, and when the next big operation came on-line (Midway), Nagumo was the Imperial Japanese Navy's choice to lead it. The command structure of the Navy was such that Yamamoto had no say in who would lead the operation.
Spruance, on the other hand, had the complete trust of his immediate superior, Vice Admiral William Halsey. Spruance had spent an unprecedented three tours in the Naval War College, and was well versed in all aspects of naval doctrine at the time. He had been Halsey's cruiser escort commander through the opening raids on the Marshall Islands, and the famous Tokyo Raid. When a skin infection sidelined Halsey just prior to the Midway operation, Halsey was asked to name his own successor by Fleet Admiral Nimitz . Unhesitatingly, he named Spruance as a 'solid' choice.
When aircraft became more capable of severely damaging or sinking large ships, they too were put into the mix of skirmishers. When the U.S. moved the Pacific Fleet from the U.S. West Coast to Pearl Harbor, it was considered an 'aggressive' move by Japan and threatened a shorter approach. Yamamoto brilliantly surmised that the new striking power of aircraft could be used to cripple the American battlefleet in the 'Decisive Battle' BEFORE it left port to respond to Japanese moves. The British success with just twenty biplane torpedo bombers against the Italian battlefleet at Taranto confirmed the efficacy of raiding ships in port.
Indeed the strike at Pearl Harbor eliminated the American battlefleet's capabilities of interfering with Japanese opening moves, but still intact were all the American aircraft carriers, their escorts, bunker fuel and repair services, and Yamamoto knew the prominence of the aircraft carrier made the 'victory ' at Pearl Harbor a hollow one. Yamamoto tried to convince his superiors to let him return to Pearl Harbor to complete the job and/or lure the remaining American forces into another battle to finish them off, but the overall elation of swift and glorious victories over the Allies in the Far East clouded the judgment of the Naval General Staff, and they put off the idea. When Doolitle's Raiders hit the Japanese homeland, however, the idea was revived, so as not to put the Emperor's residence at such risk again.
The plan to destroy the American Fleet that Yamamoto and others had worked out called for a raid/invasion of Midway Island to force the Americans to fight for something they considered indispensable, and a simultaneous invasion of the Aleutians to capitalize on the Midway distraction. A cordon of submarines north of Hawaii would alert the main Japanese fleet already steaming an interception course. Though the invasion and takeover of Midway Island would be a nice 'plum', the reason for the invasion was to draw the American fleet away from its Pearl Harbor base and defeat it in the 'Decisive Battle'. The Striking Fleet of six 'fleet' carriers was to soften up the defenses of Midway, then deal with the anticipated American carriers responding a few days later. Then the Main Body, with its battleships and heavy cruisers, would mop up the scattered remnants, and the Invasion Force would land. This timetable depended on secrecy in planning the operation so the Americans would be surprised, and good reconnaissance of Pearl to determine when the American fleet sortied to meet either invasion.
The objective of luring the American carriers out into battle was given both a favorable and unfavorable twist by the results of the recent Battle of the Coral Sea. Reports of damage to the Americans put the CV LEXINGTON as sunk, and the CV YORKTOWN as severely damaged and possibly sunk, although it was disheartening that CV SHOKAKU was badly damaged and unserviceable for the upcoming operation and that both SHOKAKU and the undamaged CV ZIUKAKU had lost a sizeable portion of their planes and pilots. Japanese Reconnaissance planes had been allowed to detect US Task Force 16's two other carriers in the South Pacific--a clever ruse by Nimitz to lull the Japanese into thinking that they were too far away to participate in, much less anticipate, the upcoming Midway operation. Still, the four large fleet carriers available should easily be able to take on the one or two American CV's thought to be near enough to respond.
Aboard the Striking Force's flagship AKAGI, en route to Midway, the objectives of the Midway mission were being discussed by Nagumo and his staff. The twin objectives of supporting the landings on Midway and destroying the responding American fleet were recognized as interfering with each other. The landings required a strict timetable to be adhered to, and interception of an enemy fleet required a flexible, timely response to contingencies. The Combined Fleet operation order gave first priority to the destruction of enemy forces, and clearly stated that the landing was secondary. As the discussion continued, the Japanese reasoned that since the enemy couldn't possibly know about the unfolding operation, that there would be plenty of time to strike Midway as scheduled and then meet the response. No reconnaissance flights were made over Pearl due to a glitch in the assigned scouting planes' refueling plan, but a cordon of submarines stationed north of Hawaii had not reported any American fleet movements in their direction. Nagumo and his staff concluded that there were no enemy forces in the area and sent out a minimum of search aircraft, all slow cruiser-launched floatplanes. Nagumo struck early in the morning at Midway with half of each carrier's planeload, prudently keeping his second strike armed with ship-killing weapons, though still below decks. So far, so good.
Spruance positioned his Task Force 16 (CVs ENTERPRISE, HORNET, and escorting cruisers and destroyers) to the northeast of Midway island, separated from Task Force 17 (CV YORKTOWN and escorts) but within mutual supporting distance, and awaited the report of the Japanese attack on Midway. Knowing that the Japanese plan called for their first attack to be on Midway itself, Halsey's (now Spruance's) staff had worked out the timing of the first American strike to attack when the Japanese Midway strike was returning to their carriers. In the Naval War College exercises they found that the carrier that struck the opposing carrier first usually gained a great advantage. Steaming towards the enemy position to shorten the return flight of his short-ranged aircraft, Spruance launched his full attack at approximately 0700-0800, with YORKTOWN's planes delayed by having to land on returning scouts. A coordinated, simultaneous attack at about 0900 by both dive bombers and torpedo planes now seemed unlikely, given other delays in launching, so the dive bombers orbiting the Task Force were ordered not to wait up for the torpedo planes, but to press on ahead. Since the American planes on Midway had taken off earlier to clear the island of aircraft before the Japanese struck, coordination of the overall attack was fast unraveling.
The scattered groups of American attack planes were having no end of troubles finding each other or the Japanese. The first group of torpedo bombers found the Japanese carriers at about 0920, but they were low on fuel and without fighter escort. Their fighter escort, out of position, requested an abort to refuel and regroup. Spruance denied the abort and ordered the attack anyway, knowing that timing is all-important. The low-level attack was slaughtered by the Fleet's defending fighters, but the scattered groups of dive bombers, by miraculous coincidence, had independently converged high above in the same piece of sky at roughly the same moment. Unhindered by defending fighters that were all milling about below after slaughtering the torpedo planes, the American dive bombers put their bombs in three Japanese carriers caught in their absolute most vulnerable potential state of ignition: fully fueled and bombed-up planes in the hangars, full gasoline hoses strewn around the deck, and dozens of stray bombs lying about due to the hasty changeover. The resulting inferno aboard AKAGI, KAGA, and SORYU put them immediately out of action.
Only the HIRYU, with a determined Yamaguchi aboard, was left untouched and ready to fight. HIRYU launched 18 dive bombers and 6 fighters as soon as they were ready. Only six dive bombers made it through to YORKTOWN but got three hits that stopped the carrier dead in the water and set her afire. HIRYU's next attack, with a mere ten torpedo planes, scored two underwater hits on what they thought was yet another American carrier (YORKTOWN underway again with fires put out) and started more fires and such a heavy list that the carrier was ordered abandoned. Though we will never know his thoughts, since Yamaguchi went down with the sinking HIRYU later that day, he must have speculated what destruction could have been wreaked on the American carrier fleet if only they had launched all four carriers' planes at the time of his urgent request. Though now all of Nagumo's carriers were sunk, the battle was not yet decided, at least in the Japanese mind.
The shock of losing his Striking Fleet spurred Yamamoto to order his trailing Main Body of heavy battleships to rush ahead to unite with Nagumo's remnants and attempt to engage in a night surface battle with their tremendous gunfire and torpedo advantage. They set an interception course for where the American carrier fleet, undoubtedly in hot pursuit, would likely be. The "Decisive Battle" could still be won by battleships. The Americans weren't cooperating, though.
Having inflicted catastrophic losses on the enemy while suffering only one damaged carrier (YORKTOWN was still afloat and about to be towed back to Pearl), Spruance had fulfilled his operational orders masterfully, but danger still lurked. It was standard Naval College practice not to endanger a carrier by allowing it to come within range of enemy gunships, so in keeping with sound carrier doctrine, Spruance ordered the Task Force to turn East away from the battle for half the night, resuming the westward advance in the morning when scout planes could locate the enemy at a safe distance. This could mean he would lose contact with a retreating enemy, but it was the essence of "calculated risk".
Yamamoto's Main Body surged forward until it was obvious that no contact would be made with the American fleet before the dawn brought renewed air attacks from Midway and the American carriers. The two fleet carriers near Alaska were too far away to assist, and the light carrier ZUIHO with the Main Body was mainly stuffed with anti-submarine aircraft and planes for a Japanese-occupied Midway. Yamamoto, realizing the objective of defeating the American fleet was now unattainable, canceled the Midway operation and then turned back toward Japan, suffering the first defeat of the Japanese Navy in centuries.
Luck was with Spruance, too, but good planning enabled good luck to take hold. Having YORKTOWN hastily patched up and added to the force was especially lucky, considering that all the damage to American CV's was absorbed by YORKTOWN alone. HORNET's dive bombers never made it to the battle scene that fateful morning, but YORKTOWN's bombers took out one large Japanese CV that may have, like HIRYU, damaged another U.S. carrier. The bold timing of the American attack was inadvertently perfect, though if the American launching had been on time in the first place, the Zeroes might have slaughtered the potent dive bombers instead. The slow torpedo bombers with their unreliable torpedoes might have attacked unopposed, but achieved little anyway. If Halsey had been in command after the four Japanese carriers had been sunk, would that aggressive commander have wisely turned back, as Spruance did, or played into the hands of the Japanese by pursuing?
Notwithstanding the luck element, which plays a part in every military operation to some degree, the adherence to the "Principle of the Objective" was the main element that allowed the commanders to achieve success or failure. Ignoring that principle, as overly cautious Chuichi Nagumo did by preoccupying himself with the Midway island attack instead of attacking the American fleet when he had the chance during the Battle, cost his country dearly. Though still powerful, the Imperial Japanese Navy lost the ability to again conduct offensive operations except on a limited scale. Concentrating on his own objectives, boldly attacking at the right moment with everything he had, and coolly ignoring the inevitable distraction of victorious pursuit, enabled an intelligently cautious Raymond Spruance to win the most decisive naval victory in the history of his country.
Dupuy, Col. T.N. Understanding Defeat. New York: Paragon House, 1990
Fuchida, Mitsuo and Masatake Okumiya. Midway: the Battle That Doomed Japan. Annapolis, Maryland: United States Naval Institute, 1955
Forrestel, Vice Admiral E.P. Admiral Raymond A. Spruance, USN. Washington D.C.: U.S.Government Printing Office, 1966
Hoyt, Edwin P. Yamamoto. New York: McGraw-Hill, 1990
Parshall, Jon, and Tony Tully, Shattered Sword,, Wash. DC, Potomac Books, 2005
Potter, E.B. Nimitz. Annapolis Md.: Naval Institute Press, 1976