Identifying Japanese ambitions of conquest is critical in understanding Pearl Harbor. Their faith instilled the belief that death was insufficient atonement for the debts they owned to Tenno. To remedy that, they believed in the participation of a divine mission to dominate all of Eastern Asia. However, the Japanese islands were severely lacking in raw materials and were highly dependent on foreign exports.
Therefore South-East Asia becomes the perfect target for its immense natural resources, capable of making Japan self-sufficient in its militaristic efforts.
Japanese expansion into China had led to never-ending guerrilla warfare. To fund its efforts, Japan becomes more desperate for sufficient resources to continue the conquest. However, South-East Asia was mostly colonial possessions of Europeans. An Anglo-French force would devastate the Japanese but with the Fall of France, South-East Asian colonies become vulnerable to conquest. With the humbling of European powers, Japan believed easy concessions by the Europeans could be achieved which would also isolate of China from foreign assistance.
So what does Japan’s conquest of South-East Asia have to do with the attack with Pearl Harbor?
Japanese-American relationships have been tense ever since WW1. The American attitude towards Japanese expansionism partly explains the attack on Pearl Harbor. Following the invasion of China, the US sent aid to China and begun restrictions on American exports. When (Vichy) France “agreed” to the occupation of Indo-China colonies, the American response was the freezing of all Japanese assets in America, followed by Britain and the Dutch East Indies.
Japan lost access to ¾ of its overseas trade and 88% of its imported oil. The US has consistently belittled Japan over history and with this latest move, the Japanese recognized an eventual American counterattack. Japanese acquisition of resources would make Japan invulnerable to American pressure. Therefore Japan’s ambitions for self-sufficiency could provoke a type of economic blockade of Japan by the American. Supported by how in the long-term, Americans would unlikely stand aside tamely and abandon China and the European empires to their fate.
Japan recognized the USA as a grave threat to their ambitions. The tremendous disparity of resources between the two nations would make any conflict a hazardous undertaking. However, because of the disparity, Japan was forced to act, knowing that if they left America to their own devices, they would be impossible to defeat in combat. The fall of France allowed the USA to redefine its national security in which a resemblance of panic emerged, where Congress passed a series of measures designed to strengthen American armed forces. The most significant was the Two-Ocean Naval Treaty. Under these terms, 4 billion dollars was committed to building tons of battleships, carriers, cruisers, destroyers and submarines, adding to the warships already under construction and the units already in commission which would effectively double the US pacific fleet.
The imperial navy realized this would make Americans dominance in the sea unchallengeable. Therefore with each year that passed, avoiding defeat by the Americans would become non-existent. In 1940, it was calculated the ratio of power was 10:7 against the Japanese but considering the Americans had to deal with Atlantic engagement, the balance of power in the Pacific seemed to be in Japanese favour. But this was undermined by the Two-Ocean Act. To match U.S production, they would have to double their own production for the program in 1942 which was impossible and too ambitious from Japan’s slender resources. “(USA) navy’s shipbuilding budget for 1940 alone excessed a decade’s worth of Imperial Japanese Navy shipbuilding budgets.” (George Baer 1996) In 1941, the navy calculated that the Americans were building three tons for every ton in Japanese yards, and that by 1944 the balance of navy power would be an disastrous 10:3 against it. The imperial Navy’s long-term prospects were bleak. As Nagumo, navy chief of staff concluded, ““The recommendation to strike immediately was based on careful study of three factors: The present strength of our forces compared to the enemy’s, the need to attack before being attacked, and meteorological considerations.”
Another strategic problem was the Philippines, an US colony. The Philippines straddled Japanese lines of communication. Reinforced American defence installations could menace any Japanese deployment southward. If the Japanese were to move against Southeast Asia, they couldn’t afford to leave their left flank, stretching thousands of miles of ocean, armed to an intact and alerted US pacific fleet at Pearl Harbor.
Therefore the Japanese believed that crucial victory needs to occur to equalise the two parties. As Nagumo concluded, “The outcome of the war depends greatly on the outcome of phase one, and the outcome of phase one depends on the outcome of our surprise attack.” During the Russo Japanese War, a surprise assault on Port Arthur was decisive in victory. Japan was able to administer a disproportionately heavy loss which falters enemy resolve while minimising the risk of its navy from counter strikes. Therefore if Japan crippled the American fleet at the outset of the war, the Japanese could comfortably conquer and consolidate their gains in reasonable security. Moreover, American production would be utilised to rebuild the losses rather than build additional ships, meaning the disparity between both nations would not come to tuition. The Japanese believed they were capable of fighting a defensive campaign in the Pacific, leading to a costly unravelling that would force a negotiated peace under a profitable compromise for the Japanese. Imperial Navy maintaining 50% or more with qualitatively superior ships, with increased logistics, strain and dispersal of the American fleet operating from the U.S coast, they could successfully create a war of attrition.
Japanese historical experience entrenched into mainstream Japanese strategy determined the Pearl Harbour attack. Japan was unable to rely on American non-intervention while feared American industrial capabilities and resource disparity. Japan concluded that America was too much of a long-term threat to ignore.
The Japanese attack on Pearl Harbour brought detrimental consequences to the Japanese war effort based on underlying flaws in the plan. Admiral Chester W Nimitz, commander of American Naval forces in the Pacific commented that the weakness of the Pearl harbor operation was that it wasn’t sustained. Nagumo, commander of the Japanese carrier withdrew from Pearl Harbor of fear of a counterattack despite Fuchida, the attack leader arguing the American defences were negligible and there were still many suitable targets to attack. While some would argue this was a major flaw, pointing that a selective second or even third strike could render Pearl Harbor unable to function as a naval base and cause catastrophic damage and the strategic victory that Japan needed. However others argue that Japan really couldn’t do much in their situation whilst problems and flaws surfacing from the attacks arguably was more detrimental than the attack itself even if a second or third strike was launched.
The concentration of attacks towards Battleship row was flawed in which the water wasn’t deep enough to hinder relief efforts. Meaning a majority of ships were able to be salvaged. Also, the battleships were incapable of operating efficiently and administering battle on equal terms against Japanese battleships. Their destruction released trained men for service in other warships which the U.S navy was desperately scarce off. However, consequentially, the attack propelled the introduction of carrier aviation in navy warfare. Before Pearl harbour, the Allied engagement against the Bismarck and the Battle of Cape Matapan proved that carrier aviation used appropriately is a necessity in naval warfare. However, the Allies lacked the foresight that that strong, numerous and properly constituted carrier forces would’ve spot and destroyed the Bismarck at a much quicker pace at minimal cost. Matapan illustrated increased effectiveness by gunnery engagement following crippling strikes from aircraft. Japan had demonstrated the usage of carrier aviation could destroy battleships from the increased range with minimal cost to themselves, making the virtue for America a necessity without any battlelines after the attack, America was handed an opportunity to rebuild their tactical formation around the carrier. Setting the stage for battleships to be rendered subordinate to carriers.
The concentration of losses among the battleships gave a distinctly misleading impression, as it disguised the fact that an overwhelming part of the US pacific fleet emerged unscathed from the ordeal. The carriers were engaged in fleet missions, taking several destroyers and heavy cruisers with them. The ramification of which was devasting for the Japanese. The submarines were unscathed, which is detrimental for Japan who desperately dependent on sea communication. While only minimal losses for the cruisers and destroyers. Some people arguing that increased engagement of the navy could’ve shifted to stronger Japanese positions. In reality, there was no theoretical action by which the Japanese could’ve rendered a major part of the Pacific fleet ineffective.
With the strategic initiative denied them, the Americans could only react with tactical offensive actions. Involving limited and peripheral carrier operations, cruiser engagement, and the unleashing of the submarines in an all-out unrestricted campaign against Japanese merchant shipping and main Japanese force. In 1941, Japan needed 10,000,000 tons of oceanic merchant shipping to sustain herself. Foreign merchant shipping made up 4,000,000 tons, which their parent nations were actively engaged in the war against the Japanese after Pearl Harbor. Even if Japan was able to capture or salvage 1,250,000 tons of shipping that was under risk, that still led to a deficit of 2,750,000 tons of merchant shipping as the result of the declaration of war, a high price for minimal damage to the US Pacific fleet. Submarines accounted for more than half of Japan’s total merchant shipping losses, bringing their empire to the brink of starvation while accounting for the loss of many warships. While the submarine campaign was a reflect action that Japan forced America to undertake, it was catastrophic for the Japanese war effort.
Pearl Harbor was complete with power stations, workshops, dockyards and oil dumps. These facilities were essential for the operation of the U.S pacific fleet. In 1940-1941, the US navy built up a reserve of 4,500,000 barriers of oil on Oahu. Most was stored above ground and vulnerable to aircraft. Had the oil dumps, and the other essential dockyard facilities been systematically attacked and destroyed, the US Pacific fleet would’ve been struggling to maintain even a minimal defensive stance in the Central Pacific. In the relief and repair efforts, the failure of destroying these facilities was imperative in preventing battleships from being repaired at the mainland and shortages of vital resources, which could’ve added a considerable amount of time in recovery. It could’ve proved prohibitive in any strategically significant move by the American fleet for several months. ‘If the Japanese sought to immobilize the Pacific fleet by the most effective and simplest manner possible, they would have been well advised to have considered attacks no on the warships but the dockyard facilities.’ (H.P. Willmott 2003). However, these statements could’ve been more exaggeration according to several factors. Facilities were damaged in the attack however it agreed it wasn’t as deliberate. Damaged ships were overwhelming for the drydocks despite minimal damages sustained. Captain Homer N Wallin, head of the salvage effort lamented shortages of supplies and skilled labourers at Pearl Harbor, meaning some ships were rebuilt at the mainland. (Logan Nye 2019) However, the universal agreement is drawn to how the outcome of the war could be significantly affected when considering the vastness of American production.
The material aspect of Pearl Harbor pales in comparison to the consequences of the galvanization of America. Japan believed the attack and destruction of the Pacific Fleet would leave Americans bewildered, frightened and divided. Believing divisions in isolationism and interventionism in the US was entrenched and a permanent feature of American political strategy. Isolationism is profoundly influential within the US but wasn’t as prominent to accept peace at any price and withstand the indignation that greeted the deaths of thousands of Americans. Isolationist sentiment dissolved overnight as Americans became united, ‘We’re never going to let this happen… And we’re going to come back, whatever the price… We’re much more committed to the idea of the country, rather than region.’ (Paul Ambrose 2001). The Japanese envisioned a firm defensive campaign until the Americans would come to terms in a compromised peace, tired of conflict. However, the generated American mentality was an only total victory or total defeat. Americans had a reason to and together and join the war effort, causing exponential growth in military force. Japan relied on their own superior resolve/moral however this attack awoken a ‘united roused democracy, which couldn’t be placated by half measures, which wouldn’t be satisfied than the destruction of the enemy.’ (H.P. Willmott 2003)