The Japanese attack on Pearl Harbor is one of the most puzzling strategic decisions of World War Two. British Prime Minister Winston Churchill found the attack “difficult to reconcile… with prudence, or even sanity,” and his criticism appears mild when measured against that in the Philadelphia Enquirer, which characterized the attack as “an insane adventure that for fatalistic abandon is unsurpassed in the history of the world.”[i] And yet, the decision was no bout of madness but a considered solution to the strategic predicament in which Japan found itself in 1941. So how does one make sense of this? That is one of the questions this paper seeks to answer. More broadly, this paper serves as an assessment of Japanese strategic decision-making in the lead-up to and during World War Two. To that end, the paper is comprised of several sections. The first looks at the lead-up to Pearl Harbor in an historical context, explaining Japan’s strategic position and the broader challenges and constraints it faced when deciding to strike the United States. The second section focuses on Japanese planning, with a particular focus on its goals upon entering the conflict. Section three briefly summarizes the results of the Pearl Harbor attack and the ensuing months of the Pacific War to assess the operation at the tactical and operational levels and to serve as a basis for evaluating the broader strategic utility of Japan’s decision. The final section is the core of the paper in which I evaluate the efficacy of Japan’s attack on Pearl Harbor in the context of its wider strategy. While the specific conclusions of the paper are detailed at length in the final section, the fundamental argument is that the attack on Pearl Harbor was a tactical success but a strategic failure. It relied upon unjustified presumptions of Japanese racial superiority and was never integrated into a broad and coherent strategic plan. The fundamental issue, however, was that the attack on Pearl Harbor was a strategic decision made for operational reasons. Thus, while it achieved its short-term goals, it unnecessarily weakened Japan’s strategic position by forcing a war with the United States that it had no clear plan to win.
The Origins of the Pearl Harbor Attack
During the late 19th and early 20th centuries, Japan experienced tremendous military success, defeating both the Chinese and Russian Empires and, as a result, expanded its territorial holdings throughout Asia. Indeed, by the end of World War I, during which Japan benefited from supporting the victorious Entente, Tokyo controlled Korea, Taiwan, the Ryukyus and Kuriles, and part of Manchuria. It was an ascendant empire, and it leveraged this status to buttress its international position, quickly joining the League of Nations and prominently serving on its Council. However, the collapse of the global economy and international trade resulting from the Great Depression led Japan to reject international cooperation and instead pursue a policy of autarky and self-sufficiency. The result of this shift was an attempt by Japan to expand its territorial holdings in mainland Asia, as Japanese leaders felt that the large resource base and Chinese market were crucial to their country’s economic security. This push to establish suzerainty over China was only magnified by the Kwatung Army, a largely autonomous Japanese army group on the Asian mainland that sought to provoke conflicts with the Chinese in order to expand further into Chinese territory. Thus, by the late 1930s, Japanese policy was largely the domain of the military and expansionist industrialists who sought financial gain from imperial conquest and growth in military expenditure.[ii]
The critical tipping point occurred in 1937, the point at which Japan’s military-dominated government dragged the country into full-scale war in China. This adventure was naively expected to yield a swift and easy victory, but it quickly deteriorated into a strategic nightmare, as Japan simply lacked the manpower and logistical capacity to project adequate force into the Chinese heartland. As the conflict dragged on into 1938, Japan increasingly found itself in a difficult strategic situation in which almost all of its resources were tied up in a protracted struggle in the vast land expanse of China. In 1937, for example, Japanese military expenditure was 69% of all government spending, and this number only grew over the following years![iii] By 1941, moreover, Japan had committed 31 of its 51 divisions to the mainland, leaving only 40% of its forces available for other contingencies.[iv] This precarious position was further magnified by lingering concerns about a potential conflict with the Soviet Union in Manchuria. Indeed, several border skirmishes erupted while Japan was still embroiled in China: In 1938 the Kwantung Army initiated a border conflict with Soviet soldiers in disputed territory around Manchuria in an incident that came to be known as the Changkufeng Incident, and in 1939, conflict between Japanese and Soviet forces resurfaced during the Nomonhan Incident.[v] Both skirmishes ended in Japanese defeat, prompting Japanese military leaders to grow even more fearful about their strategic situation. In short, Japan found itself overextended and increasingly in conflict with its powerful neighbors.
This growing Japanese bellicosity worried American policymakers, as they feared for the security of the Philippines, an American colony at the time. The situation from the American perspective became increasingly dire in the late summer of 1940, however, as it was at this point that Germany began its rampage through Europe. Even though the United States had not yet entered the war, it was carefully following events and slowly increasing its support of the United Kingdom through policies like the Destroyers for Bases Agreement. The primary source of American disquiet was a concern that Japan might exploit the weakened state of European countries to expand into the European colonies of Southeast Asia – indeed, Japan did pressure Vichy France to allow Japanese troops into French Indochina.[vi] This would place British possessions like Singapore and India at risk, increase the danger to the Philippines, and raise the possibility of a general Pacific War.[vii] U.S. State Department officials also feared that continued Japanese expansion into China and Southeast Asia would hurt U.S. trade access to the region, as Tokyo was blocking shipping along the Yangtze and introducing new currency into China that made it difficult for non-Japanese imports to enter.[viii] By the spring of 1939, therefore, the Unites States Congress was pushing legislation to block the sale of steel and iron scrap metal to Japan. Following this escalation, President Roosevelt allowed the US-Japanese Trade Treaty to expire without renewal, which opened the door to a full embargo of Japan.[ix]
These moves spooked the Japanese, as they desperately needed American raw materials to support their war effort and military buildup. Indeed, 80% of Japanese oil and 75% of its scrap iron was sourced from the U.S.[x] However, the deciding blow was delivered in 1941. During the previous year, Roosevelt had restricted the sale of aviation fuel, scrap iron, potash, copper, brass, and other metals to Japan, but he had refused to embargo oil for fear that the inclusion of this precious resource would permanently destroy relations with Japan and increase the risk of Japanese adventurism into the oil-rich Dutch East Indies.[xi] The German invasion of the Soviet Union in the summer of 1941 changed these calculations, however, as Roosevelt began to receive intelligence from MAGIC, the American decryption program, that Japan was contemplating an invasion of the Soviet Union. The concerns were only exacerbated by Japan’s decision to join Germany and Italy’s Tripartite Pact in September of 1940.[xii] As one analyst in the State Department explained, “[Tokyo] cannot be expected to forget what they have for many years considered as the Russian dagger pointed at the heart of Japan.” The report concluded that although Japan’s future war plans were still ambiguous, they were “far more likely… to be in the direction of action against Russia.”[xiii] This was tremendously distressing for American policymakers, as they felt that Japan creating a second front for the Soviets would all but guarantee Nazi dominance across all of Eurasia. In response, hardliners within the American Department of State and Treasury exercised their control over trade regulations to interpret Roosevelt’s call to freeze all Japanese assets in such a way as to impose a complete ban on American oil exports to Japan.[xiv] Japanese leaders knew this ban would put them in dire straits, as their strategic reserves were rapidly diminishing. Indeed, Prime Minister Tojo noted that “Two years from now we will have no petroleum for military use. Ships will stop moving… We can talk about austerity and suffering, but can our people endure such a life for a long time?… I fear that we would become a third-class nation after 2 or 3 years if we just sat tight.”[xv] Consequently, they earnestly began planning a military campaign to achieve economic security and improve their strategic position.
Planning to Strike
Given the rapidly deteriorating strategic situation confronting Japan, the leadership in Tokyo began planning potential military options for redressing the situation. It should be noted that throughout the military planning phase, Japanese politicians and diplomats were concomitantly working to obviate the need for war. However, their sincerity was questioned by American policymakers who observed Japan’s continued buildup of military forces for operations in Southeast Asia, which U.S. Ambassador to Japan Joseph Grew repeatedly flagged in his cables to Washington.[xvi] As a result, Japanese attempts to avert war were repeatedly stymied, and the likelihood of conflict continued to grow.
As Japanese leadership developed its plan to break free from the American economic chokehold, it became increasingly apparent that an invasion of the resource-rich European colonies in Southeast Asia was essential to Japan’s long-term strategic position. The question, however, was how best to acquire these precious territories while minimizing the risk to Japan. Although Japan’s civilian government was staffed with officials, such as Foreign Minister Togo and Finance Minister Okinori, who were averse to conflict with the United States, they were largely shut out of the strategic planning by the military.[xvii] Prime Minister Tojo was also the Army Minister, granting the military inordinate influence within the cabinet.[xviii] This bias in favor of the militarists, combined with the extreme autonomy enjoyed by the Japanese military – they had initiated several coups in prior years and had also provoked conflict in Manchuria without the approval of civilian leadership – undermined the influence of the more pacifist voices within the cabinet.[xix]
As the plans developed, two competing proposals emerged. The first plan was to launch coordinated attacks on Malaya and the Dutch East Indies to appropriate and secure their oil and rubber resources. Significantly, this proposed operation would bypass the American-held Philippines in an attempt to avoid war with the United States. The Imperial Japanese Army (IJA) was in favor of this plan, as they felt that the risk posed by American forces in the Philippines, under this scenario, was relatively small. First, they believed it fairly unlikely that the United States would risk a war in the Pacific given the situation in Europe. They therefore had no desire to draw the U.S. into a war. Additionally, they felt that even if the Americans did choose to challenge the Japanese aggression in Malaya and the Dutch East Indies, the paucity of American naval and air forces in the Philippines meant that the risk to the Japanese invasion fleets was relatively low.[xx] The Navy emphatically disagreed, arguing that it was imperative to secure the Philippines in order to protect the Southeast Asian battlespace from an American intervention. As a result, the Navy lobbied for a modified version of the Army plan that included attacks on the Philippines and, fatefully, the American Pacific Fleet at Pearl Harbor.
Interestingly, the civilian Minister of the Navy, Shimada Shigetaro, was strongly opposed to war with the United States.[xxi] In what was by this point a commonplace circumstance in Japan, however, his views were ignored and bypassed by the Imperial Japanese Navy (IJN), which was nominally subordinate to him. Commander of the Combined Fleet Isoroku Yamamoto threatened to resign if the IJN’s preferred approach was not adopted,[xxii] and Suzuki Teiichi, a retired lieutenant general who served as the general director of the Cabinet Planning Board, intentionally misled the civilian leadership about the feasibility of conflict with the U.S. in order to garner their support for a war.[xxiii] Thus, by late October, even many of the formerly dovish Cabinet members had begun to accede to the merits of a conflict with the United States.[xxiv]
The plan devised by the Japanese military was forced to contend with Japan’s manpower shortage, which was a result of the still fierce conflict in China. The IJA pledged 20% of its total strength – 12 divisions and 4 brigades, supported by 2 air groups composed of 700 aircraft – for the Southeast Asian campaign. British Hong Kong and Malaya, along with the American Philippines, were to be taken in the first stage of the campaign. Once these areas were secured, The IJA would then move to occupy the Dutch East Indies. Meanwhile, Japanese Marines were tasked with taking the American island bases of Wake Island and Guam.[xxv] The opening move of this grand plan, of course, was the attack on the U.S. fleet at Pearl Harbor. This attack was to be conducted by a task force based around six carriers and their 417 aircraft, and it hoped to achieve three major objectives.[xxvi] First, it was designed to support the broader Japanese push south by damaging American naval capacity to the point that it could not be quickly deployed to defend the Philippines. Second, the attack sought to improve Japan’s strategic situation by destroying enough ships to offset the American naval buildup to an impactful degree.[xxvii] Finally, Japanese officials hoped that the attack would demoralize the American public and lead Roosevelt to acquiesce to some kind of settlement regarding Japan’s position in Asia.[xxviii]
But even if the attacks did not move the U.S. to sue for peace, the Japanese leadership felt that the attack on Pearl Harbor and, later, the American island outposts of Guam and Wake Island would stun the United States Navy long enough to allow Japan the time it needed to expand throughout Southeast Asia and fortify its island holdings in the Pacific. The hope was that by the time the U.S. ramped up its economy to meet the demands of a large-scale war, Japan would be so ensconced in Southeast Asia and the Western Pacific that the United States would seek a negotiated settlement rather than pay the cost in lives and money needed to root out Japanese forces.[xxix] This view was not entirely without merit. After all, Japan had more warships of every class than the U.S. Pacific Fleet: it had twice the number of fleet carriers and four more light carriers, a battleship advantage of 5:4, twice as many cruisers, and nearly three times as many destroyers.[xxx] However, this advantage would not endure, as The Two Ocean Navy Act of 1940 committed the U.S. to increase its tonnage by 70% – in part by constructing 18 new carriers, 6 new battleships, and 33 more cruisers – by the mid-1940s.[xxxi] Japanese Army Chief of Staff Hajime Sugiyama also warned that “the ratio of armaments between Japan and the United states will become more unfavorable… as time passes; and particularly, the gap in air armament will enlarge rapidly.”[xxxii] In other words, if Japan were to attack, it had to act soon because any delay would allow the U.S., with its enormous industrial capacity, to build an insurmountable advantage. Japan also held the advantages of surprise and geographic proximity, as it could decide when the war began and quickly move forces throughout Southeast Asia from its bases in the Pacific and China. Despite these advantages, the plan was still fraught with risk given the sheer strength of the U.S. economy: United States GDP was 5.7 times that of Japan in 1941 and 10.24 times as large by the end of the war in 1945.[xxxiii] Indeed, Suzuki privately acknowledged that:
Japan has not established a defensive system, has no long-term plans for material sustenance of the state, and has dealt with the distribution of materials on a year-by-year basis… For 1942, we project the material supply to be 90 percent of what it was for … That would mean depleting all the present stock.[xxxiv]
The Japanese also had no plan to end the conflict, as they realized they could not defeat the U.S. in a total war and had no way to meaningfully hold the American homeland at risk. Thus, their entire strategy rested on a naïve and somewhat racist belief that Americans, as a result of their decadent culture, would have neither the will nor the tenacity needed to push into Japanese-held territory. In short, Tokyo’s plan was to hit the U.S. hard and then dig in. The Japanese were hoping and betting against considerable odds that the U.S. would seek a negotiated peace because absent this occurrence, there was little Japan could do to end, let alone win, the war.
The Plan in Action
December 7, 1941 was, in the words of U.S. President Franklin Roosevelt, a day that shall live in infamy. In the early morning hours, fighters, torpedo bombers, and dive bombers from Japanese carriers attacked Pearl Harbor in two waves. The result was the destruction of 47% of U.S. aircraft in Hawaii and damage to another 40%. Japanese planes also hit the base’s eight U.S. battleships hard, damaging all and inflicting so much damage upon the Arizona and Oklahoma as to permanently knock them out of the war. The 38 smaller surface combatants suffered only minimal damage, allowing all of them to survive the attack. Japanese aircraft also failed to strike the American fuel depots and drydocks at Pearl Harbor, leaving much of the Pacific Fleet’s logistical and support infrastructure intact. Additionally, Japanese aviators failed to destroy any U.S. carriers, as they happened to be out of port during the morning of the attack. Despite these shortcomings, the strike must be considered a tactical success: It maintained the element of complete surprise from planning to execution, inflicted heavy damage upon the United States’ Pacific battleships, and resulted in a loss to Japan of only 29 aircraft and five midget submarines.[xxxv]
The success of the Pearl Harbor operation also guaranteed the short-term security of Japan’s invasion of Southeast Asia. Indeed, the Japanese saw fantastic successes early on, capturing Malaya, Singapore, the Philippines, the Dutch East Indies, and eventually most of Burma. While it is easy to pan the short-sighted nature of the attack by pointing to America’s massive industrial potential, the harm wrought to the American fleet was far from trivial: it induced caution among American admirals and damaged every Pacific battleship to some degree. Thus, even a year later, after defeats at both Midway and the Coral Sea, Japan still possessed more carriers, battleships, and cruisers in the Pacific than the United States. To emphasize this point, it is noteworthy that in the autumn of 1942, Japan had eight operational carriers to America’s one.[xxxvi] This was extremely important, as Japanese crews were generally better trained, and Japan’s pilots were absolutely superior. Thus, the IJN already enjoyed a clear qualitative advantage at the onset of the war, so the quantitative advantage that was extended through the attack on Pearl Harbor served only to amplify Japan’s early operational advantages. It does not follow, however, that the attack was the optimal long run decision. Tactical and operational successes are certainly important, but without sound strategic guidance they are largely superfluous. After all, a country may win many battles and still lose the war.
Evaluating Japan’s Strategic Choices
Before offering a strategic analysis of Japan’s decision to bomb the American fleet at Pearl Harbor, it is worthwhile to briefly review Japan’s pre-war position. Tokyo found itself embroiled in an intense war in China that was draining equipment and manpower at an alarming rate, faced increasing economic sanctions from the United States, and enjoyed a clear military advantage within the Western Pacific. With European nations focusing all of their efforts against the Nazis and, in most cases, failing to halt the German onslaught, the European-controlled Southeast Asian territories replete with strategic resources like oil and rubber lay completely exposed. This presented a tempting target for Japanese leaders, as occupation of these European holdings would simultaneously strengthen Japan’s position in Asia and solve its worrisome resource problems.
In consideration of these facts, it becomes clear that Japanese leadership faced little choice but to occupy at least a portion of Southeast Asia. Were Japanese leaders to accede to U.S. demands, pulling out of China and forgoing any more territorial expansion lest this trigger more crushing American economic retaliation, it would effectively neuter their strategic autonomy and ensure that their country remained dangerously reliant on access to American resources for the indefinite future. This exact concern was voiced by IJA Vice Chief of Staff Tsukadu Osamu, who noted that “a troop withdrawal from southern Indochina won’t happen… [because] if we withdrew, the United States would have its way. Then it could interfere with us anytime it wanted.”[xxxvii] Reason puts it well when he writes that “The United States was, in effect, demanding that Japan renounce its status as an aspiring great power and consign itself to permanent strategic dependency on a hostile Washington. Such a choice would have been unacceptable to any great power.”[xxxviii] Thus, some kind of occupation of the resource-rich European colonies was clearly in Japan’s strategic interest, as this would be the only way to ensure the Japanese economic security so important for enabling Tokyo’s military power and international status.
The less obvious question is this: How should Japan have executed this southern strategy? It is here that Japan’s leadership made their biggest mistake, as they confused operational preferences with strategic imperatives. Instead of deliberately instigating conflict with the United States, Japanese leaders should have attempted to address their resource concerns without precipitating an outright war with the American industrial giant. One way they could have achieved this end would have been simply to adopt the IJA’s preferred plan to advance into Southeast Asia while bypassing the Philippines and canceling the strike on Pearl Harbor. By the autumn of 1941, Japan already occupied all of French Indochina and could have easily occupied the Dutch East Indies given that Holland lay under the boot of German occupation. An attack on British holdings in Malaya would have been somewhat more perilous given the importance Roosevelt assigned to the survival of Britain against the Nazi onslaught. However, it is noteworthy that similar threats to the United Kingdom’s security and very survival, such as the German Blitz, did not precipitate an American entry into the war. Even at this point, the United States remained rife with isolationist sentiment, and it is extremely doubtful that Roosevelt could have garnered the popular and Congressional support needed to declare war on Japan over something as seemingly trivial and distant as the Dutch East Indies or British Malaya. Moreover, one must not discount that Roosevelt was focused almost exclusively on the threat from Nazi Germany. He was not seeking a protracted military entanglement in the Pacific and would likely have made every possible effort to avoid one.[xxxix] Thus, Japan could very likely have poached even British Singapore without risking large scale war with the United States. But instead of taking limited actions that might have ignited a limited conflict with the United States, Japanese leadership obtusely embarked upon a series of actions that effectively guaranteed an all-out war with the greatest economic leviathan of the time.
As the war dragged on, the idiocy inherent in this choice revealed itself with increasingly clarity. There was little that Japanese leaders could do, however, as they had guaranteed a fight to the death by attacking not simply an American colony, but a United States naval base staffed by American sailors and civilians. The attacks on Pearl Harbor, as successful as they were on a tactical level, created an alarmingly palpable belief among the American populace that they were under direct threat. Despite their aversion to war, therefore, the population was mobilized by Pearl Harbor in a way that little else could have, awakening a giant that Japan could not hope to slay. For all the short-term advantages Japan accrued by catching the Pacific Fleet unprepared, the long-term consequences were far worse and far more significant. In 1943 alone, U.S. industry answered the call to war and built 2 battleships, 6 fleet carriers, 9 light carriers, 24 escort carriers, 4 heavy cruisers, 7 light cruisers, 128 destroyers, and 200 submarines. And over the course of the entire conflict, the U.S. produced an astounding 24 Essex-class fleet carriers, which were unmatched by any craft in the Japanese fleet.[xl] To put this output in its proper context, the U.S. produced more ships for the Pacific theater in the four years of war than had previously existed in its pre-war Pacific Fleet. This meant that by 1944 the U.S. Pacific Fleet alone was more than twice the size of the entire IJN. Not only were U.S. ships greater in number, they were also generally of superior quality. This is perhaps most obvious in the field of submarines, where America’s 70 Gato-class and 122 Balao-class fleet submarines were deployed to devastating effect against Japanese shipping.[xli] In fact, the Japanese Planning Board anticipated these losses to some degree but concealed them from the Cabinet. But even Japan’s worst-case forecasts significantly underestimated the damage wrought by American submariners: The Planning Board privately thought Japan could lose 700,000 tons of shipping a year, but the actual numbers were almost double this estimate (even subtracting for new shipping capacity built during the war).[xlii]
Japan also faced a deeper problem, which was that its military had no plans for extricating itself from the war in China. During the negotiations with the U.S., for example, the Japanese leadership proposed withdrawal dates of between 25 and 99 years in the future. Of course, this inability to disengage from the messy war in China partially explains Japan’s decision to embark on a war with the U.S. in the first place. Its rapidly diminishing stock of strategic resources needed to be replenished from sources to the south. However, the inability to remove troops from China was also part of the reason that Japan had little chance of success against the U.S. As late as August of 1945, 56% of the Japanese Army deployed outside the home islands was in China and Manchuria, not in the Pacific.[xliii] Simply stated, Tokyo did not possess the requisite manpower to fortify and develop enough island outposts to keep the U.S. at bay. With so much of its force tied down on the Asian mainland, in other words, Japan’s entire defensive perimeter strategy ceased to make much strategic sense because Japan lacked the manpower to implement it effectively. Ironically, Japan’s solution to its resource problem only exacerbated the underlying problems it faced. By fighting not only the Chinese nationalists but also the United States, Tokyo invited a scenario that rendered its manpower crisis that much more acute. And by exposing its shipping capacity to U.S. air and naval power, Japan actually ended up reducing its access to vital resources. At its greatest extent, the Japanese Empire was 6,400 miles wide and 5,300 long, and it encompassed particularly rugged, inaccessible terrain in place like Burma.[xliv] For reasons not entirely clear, Japanese leadership never gave much pre-war consideration to the logistical challenge this would pose, and thus they proved consistently unable to adequately resource a large number of their troops. This failure would be intolerable in any conflict, but Japan’s inability to efficiently maximize resource distribution in a war against an industrial titan like the United States is simply inexcusable.
As the U.S. onslaught intensified, Japanese leaders clung stubbornly to their pre-war plan of inflicting as much damage as possible on the American fleet early in the war and then riding out the storm. And while they changed their tactics on the margins, adopting a friendlier approach to the natives of occupied territories to garner their support and cooperation against the Americans, this was a case of too little too late. Japan’s earlier savagery against these populations made reconciliation nigh impossible.[xlv] And even had Japan been able to increase the level of trust and comity that existed between its occupying armies and local populations, this would not have significantly changed the strategic situation facing Japan. The inanity of Japan’s defense perimeter strategy extended to the method they employed to defend their island outposts. As D. Clayton James notes, “Instead of developing clusters of mutually supportive island bases around their Pacific perimeter, Japanese commanders were ordered to prepare concentrated defenses on single islands separated by large distances and with vulnerable lines of communication.”[xlvi] These isolated garrisons, though tenacious, simply had no chance of repelling U.S. amphibious forces, especially when the U.S. island-hopping campaign simply bypassed most Japanese-held islands. By failing to properly resource and support its garrison and choosing not to develop an integrated, comprehensive and thorough defense in depth strategy of mutually-supporting islands, Japan only further weakened its ability to defend against U.S. forces. Given that a strong defense comprised the entirety of Japan’s post-Pearl Harbor strategy, this failure proved to be one of calamitous enormity.
Of course, much of the aforementioned information concerns events post-Pearl Harbor, so one might wonder about its relevance. But this is the point: Pearl Harbor was just a small part of Japan’s overall strategy, lasting only a few hours. It therefore must be considered within the broader context of the Pacific War. While the attack on the Pacific Fleet was technically brilliant and fairly well executed, it seemed to be largely viewed in a vacuum by Japanese decisionmakers. The implications of the attack on broader Japanese strategy were never fully appreciated, and Japanese planning never understood the full magnitude of a war with the United States. By focusing inordinately on the short-term operational objectives of securing supply lines and impeding the ability of the Pacific Fleet to sally forth into the South China Sea, the Japanese forgot to fully account for – or simply chose to ignore – the immense strategic burden an attack on the United States would create. From logistical requirements to industrial capacity to manpower, Japan was woefully unprepared.
Consequently, the attack on Pearl Harbor was also not as strategically decisive as it needed to be. It temporarily eliminated most of the American battleships and helped to grant the IJN numerical superiority for several months beyond what it otherwise would have enjoyed, but it absolutely did not decisively degrade American sea power. For all the quantitative naval advantages Japan possessed in the first year of the war, its Pearl Harbor attack failed to eliminate any of the smaller surface combatants of the Pacific Fleet. The attack also left the logistical support facilities, such as drydocks and fuel depots, that proved so crucial to the early American war effort completely intact. Simply put, the Pearl Harbor attack was far too minuscule to decisively shift the direction of the war even despite its visionary brilliance and tactical success. To really stand a chance against the American juggernaut and buy enough time for its defensive strategy to bear fruit, Japan would have had to eliminate almost the entire Pacific Fleet and most of its support infrastructure. It did not, nor could it have, and thus the attack on the American fleet was of very limited strategic value.
Given these multiple failures, one is forced to grapple with how Japan bungled its strategic planning so severely. The answer seems to be that there simply was no rigorous strategic planning by the Japanese military or civilian leadership. While there were certainly isolated voices vociferously opposing war with the United States, most in the Japanese leadership seemed to have a fatalistic resignation about the inevitably of conflict with their rivals across the Pacific. This is somewhat understandable – Japan and the U.S. were increasingly coming to blows – but the logic was quite circular. Japanese leaders seemed to believe that “the policy of the southern advance would make conflict with the U.S. inevitable; since war was bound to occur, Japan should advance southward to prepare for the conflict.”[xlvii] What is exceedingly less understandable is Japan’s motivation for deliberately striking U.S. forces at Pearl Harbor, thus mobilizing the American public for a large-scale war. After all, American isolationist sentiment and fixation with counterbalancing Nazi Germany would have likely resulted in only a limited response to Japanese expansion. Why would Japan intentionally provoke an almost unwinnable war when it could likely be avoided? To answer this question, one must look back at the leadership, which was composed largely of either active or former military officers. As a result, much of the initial planning – especially that by the Navy – was disproportionately focused on the operational, as opposed to the strategic, level of war. The IJN was so concerned about the potential of American attacks against its forces in Southeast Asia that it felt compelled to launch a pre-emptive attack against American positions even if this guaranteed a bigger strategic challenge in the long-run. This decision appears even more obtuse when one realizes that the operational success of Japan’s invasion into Southeast Asia did not require a surprise attack on the Pacific Fleet: Even had America intervened – which is doubtful – it would have required at least six months to gather sufficient oilers and support vessels to support large operations near Japan.[xlviii] In short, to ensure the success of a single campaign, Japan put itself in a position to lose the entire war.
Japan made a fateful choice by choosing to strike the U.S.-held Philippines and, more consequentially, the Pacific Fleet at Pearl Harbor. By deliberately attacking American territory and forces, Tokyo guaranteed a conflict with the most powerful economy in the world. As a result, the Japanese attack on Pearl Harbor cannot be understood in a vacuum; it must be placed within the broader strategy of the Japanese Empire. As noted throughout this paper, Japanese leadership faced a particularly vexing situation in the leadup to war with United States: its forces were bogged down in an interminable war with the Chinese and its access to strategic resources like oil and metals was being increasingly constricted by American trade embargos. These pressures meant that some kind of imperial expansion was required to secure Japan’s economic base and position as a great power. Acquiescence was simply not an acceptable option for a proud, rising power like Japan, especially given the dominant position of pro-expansion militarists in its government. However, the particular manner in which Japan chose to pursue this expansionary path was horribly short-sighted and reveals the dearth of proper strategic thinking among senior decision-makers in Tokyo.
Japanese leaders, by striking at the U.S. Pacific Fleet, invited a war with a significantly more powerful country that otherwise would likely have begrudgingly tolerated limited Japanese expansion into Southeast Asia. This strategic folly was compounded by the problem that Japanese leaders significantly underestimated, or willfully ignored, the immense strain upon its resources, both human and material, that a war with the United States would create. This would be consequential even if Japan were fighting only the United States. In fact, the situation facing Japanese leadership was far direr, as they had to fight the U.S. while also engaging in a large-scale conflict in China and expanding into Southeast Asia. As a result, Japan faced the American giant while significantly overstretched and under-resourced, and it therefore could not effectively implement its plan to create a durable defensive perimeter around the Japanese home islands and Southern Resource Zone.
As noted throughout, the Pearl Harbor attack was brilliantly executed. It masterfully employed a new class of warship, the carrier, to great effect, and it achieved many of its tactical objectives. For all its cunning, however, the plan made little sense when incorporated into Japan’s overall strategy, as it needlessly provoked a total war with the one power Japan absolutely could not afford to fight. Japanese carrier aviators were given the impossible task of destroying American naval power to such a degree that, even with America’s immense industrial capacity, the IJN could have overwhelming Pacific dominance long enough for Japan’s defensive perimeter strategy to be successfully implemented. Even if everything had gone perfectly – Japanese planes were able to sink the American Pacific carriers and severely damage Pearl Harbor’s infrastructure – it is still unlikely that Japan could have won because it simply lacked the capacity to conduct a war on the scale that was required. Its armies were trapped in China, its growing empire created ever more strain on its logistical and industrial capacity, and it faced the greatest economic power of the time. The Pearl Harbor attack is a testament to the excellence of Japan’s naval aviators, its tactical creativity, and the importance of luck. Far from improving Japan’s already difficult strategic situation, however, the attack needlessly destroyed Japan’s position for little more than a cheeky tactical victory and short-term operational gain.
[i] Scott Sagan, “The Origins of the Pacific War,” Journal of Interdisciplinary History 18, no. 4 (1988), 893.
[ii] D. Clayton James, “Strategies in the Pacific,” in Peter Paret (ed.) Makers of Modern Strategy, 704-705 (Princeton, N.J.: Princeton University Press, 1971).
[iii] Alan Schom, The Eagle and the Rising Sun (New York, N.Y.: W. W. Norton & Company, 2004), 60.
[iv] Williamson Murray and Allan Millett, A War to Be Won (Cambridge, M.A.: Belknap Press, 2000), 167.
[v] Jessica L. P. Weeks, Dictators at War and Peace (Ithaca, N.Y.: Cornell University Press, 2014), 124-126.
[vi] D. Clayton James, 706.
[vii] Jeffrey Record, Japan’s Decision for War in 1941: Some Enduring Lessons (Carlisle, P.A.: Strategic Studies Institute, 2009), 14.
[viii] Dale C. Copeland, Economic Interdependence and War (Princeton, N.J.: Princeton University Press, 2014), 175-176.
[ix] Ibid., 177.
[x] Ibid., 178.
[xi] Record, 15.
[xii] Ibid., 12.
[xiii] Foreign Relations of the United States (Washington, D.C., U.S. Government Printing Office, 1941) 4:276-277; 983-984.
[xiv] Record, 17.
[xv] Quoted in Nobutake Ike, Japan’s Decision for War: Records of the 1941 Policy Conferences (Palo Alto, CA: Stanford University Press, 1967), 238.
[xvi] Copeland, 218.
[xvii] Eri Hotta, Japan 1941 (New York, N.Y. Vintage Books, 2013), 216-217.
[xviii] Ibid., 220.
[xix] John Toland, The Rising Sun (New York, N.Y., Random House, 1970), 1-14.
[xx] Murray and Millett, 172.
[xxi] Hotta, 225.
[xxii] Murray and Millett, 172.
[xxiii] Hotta, 224-225.
[xxiv] Ibid., 228.
[xxv] Murray and Millett, 172-173.
[xxvi] Alan Zimm, Attack on Pearl Harbor: Strategy, Combat, Myths, Deception (Philadelphia, P.A.: Casemate Publishers, 2011), 83.
[xxvii] H. P. Willmott, The Barrier and the Javelin: Japanese and Allied Pacific Strategies, February to June 1942 (Annapolis, M.D.: Naval Institute Press, 1983), 14.
[xxviii] Zimm, 372.
[xxix] Victor Davis Hanson, The World Wars: How the First Global Conflict Was Fought and Won (New York, N.Y.: Basic Books, 2017), 145.
[xxx] Ibid., 142-143.
[xxxi] Spencer Tucker, ed., Encyclopedia of World War II: A Political, Social, and Military History (Santa Barbara, CA: ABC-Clio, 2005), 1541.
[xxxii] Record, 25.
[xxxiii] Hanson, 455.
[xxxiv] Hotta, 223.
[xxxv] Murray and Millet, 178.
[xxxvi] Hanson, 143-144.
[xxxvii] Hotta, 237.
[xxxviii] Record, 21.
[xxxix] David Evans and Mark Peattie, Kaigun: Strategy, Tactics, and Technology in the Imperial Japanese Navy, 1887-1941 (Annapolis, M.D.: Naval Institute Press, 2012), 493.
[xl] Hanson, 153.
[xli] Ibid., 189.
[xlii] Hotta, 223.
[xliii] D. Clayton James, 715.
[xliv] Ibid., 717.
[xlv] Ibid., 714.
[xlvi] Ibid., 719.
[xlvii] Akira Iriye, Across the Pacific (New York, N.Y.: Imprint, 1967), 208.
[xlviii] Zimm, 373.