The Consequences of Pearl Harbor

The Japanese attack on Pearl Harbor precipitated the entry of the U.S. into World War II. While a tactical success (with some major exceptions in that regard), it was a massive strategic blunder. Japan, by adding the neutral U.S. to its list of enemies, ensured its defeat and partial destruction within less than four years.

The attack was motivated by a perception on the part of the Japanese government and military (which were almost the same entity) that the U.S. would at some point no longer tolerate Japanese imperialist expansion in the Western Pacific and East Asia. This may have been true, but the Japanese made a bad miscalculation. The U.S. public had no appetite for war, and public opinion polls showed time after time a strong isolationist sentiment. The U.S. had its Philippines outpost near Japan, but that was not a military threat to Japan’s expanding empire. In short, Japan could probably have continued to run amok in the East Asia theater; the only power opposing them, Britain, was fighting for its life in Europe and was no real obstacle, as was shown by post-Pearl-Harbor events. But the Japanese were angered by U.S. embargoes of strategic materials such as oil and steel. Japan itself was resource-poor in terms of the materials needed to support a modern army, navy, and air force, and the lands it had conquered were similarly deficient. The islands of present-day Indonesia offered one of the sole available sources of petroleum, for example. Thus, Japan felt that it would need time to exploit its conquered lands. This time, it was felt, could only be bought by destroying the U.S. Pacific Fleet.

Much is made of the fact that the Pearl Harbor attack (and the Clark Field attack in the Philippines, which was arguably a worse and more damaging defeat) was such an utter surprise to the American military. The truth, though, it that it wasn’t all that much of a surprise that Japan would attack; radio intercepts and code-breaking had strongly suggested that Japan was about to undertake one or more major military offensives. The only question was where, and Pearl Harbor was a surprise simply because it was such a stupid thing for Japan to attempt. Even if successful, it was just about the worst move Japan could try. As Roberta Wohlstetter notes, “…it is not true that we were caught napping at the time of Pearl Harbor. Rarely has a government been more expectant. We just expected wrong” (Wohlstetter, “Pearl Harbor,” 4). Strategically, it was a blunder. Diplomatically, it was a horrific blunder. Tactically, it happened to work.

It should be noted that based on the knowledge of Japanese capabilities available at the time, any attack on “Battleship Row” was considered to be likely to fail. Pearl Harbor was a shallow anchorage. Aircraft-launched torpedoes were thought to need a greater depth than that of Pearl Harbor to be successfully dropped. Thus, no torpedo nets were rigged around the battleships. The Japanese did not have an effective dive bomber that could be launched from an aircraft carrier, so the ships were considered to be impervious to air attack. The Japanese had, in fact, developed a shallow-water torpedo, specifically for use at Pearl Harbor. But it was developed in great secrecy. Navy planners had no reason to believe that the Japanese had such a weapon.

The Pearl Harbor attack was by no means a complete success. Most crucially, the attack failed to catch any of the U.S. carrier fleet, all of which were at sea at the time of the attack. These carriers would prove pivotal in the turning of the tide at the Battle of the Coral Sea, Midway, and Guadalcanal. Had those carriers been sunk, it is likely that the U.S. would have been unable to mount offensive operations in the Pacific until 1943, giving Japan the time it needed to consolidate its conquests. Just as damaging was the fact that Pearl Harbor itself remained a functional air and naval base. The attacking aircraft did not bomb the naval repair facilities or the petroleum tanks, nor was there major damage caused to the airbase and hangar facilities. Thus, when the carriers returned and the base was resupplied, Pearl Harbor was ready to enter the fight.

There is an interesting angle to consider from the fact that the Pacific battleship fleet was destroyed but that the carrier fleet survived. Battleships were becoming obsolete; naval air warfare was the wave of the future. Pearl Harbor forced the U.S. into strategic carrier warfare as its new Pacific doctrine. This wasn’t immediately apparent; even well after the war; for example, Wohlstetter, in a comparison of the Cuban missile crisis and Pearl Harbor, wrote that “At the least, Pearl Harbor was a catastrophe, a great failure of warning and decision. […] It is true…that we had lots of information about the approaching crisis (Wohlstetter, “Cuba and Pearl Harbor,” 691). This, however, misses the point. Pearl Harbor could have been a catastrophe; instead, it was a military defeat from which the U.S. easily and swiftly recovered. Likewise, there was actually a lot of warning that something was going to happen, but one cannot guard against every contingency, only the likely ones. Also, it should be noted that the carriers, even when docked, were never put in the same vulnerable position as the capital ships on Battleship Row. This suggests that local commanders realized that the carriers were more vital than the battleships. Certainly, Japanese battleships later in the war fared very badly against American ship-based aircraft.

The immediate political consequences of the Pearl Harbor attack were swift and profound. Almost literally overnight, the mood in America changed from staying on the sidelines to active, enthusiastic participation in the war. The war effort galvanized the American public; it also had the unforeseen effect of providing a huge jolt to the economy. As Sylvia Whitman related, “The new defense business brought a welcome end to the poverty of the Great Depression…In 1933, unemployment…stood at 24.9 percent…By 1941, unemployment had dipped to 1.2 percent” (Whitman, 19). Certainly, the Japanese had underestimated the sheer quantities of war materiel the U.S. could produce; once the U.S. was revved up to full production, Japanese defeat was just a matter of time. Also, the stated U.S. policy throughout the war was “Germany first.” Japan had had no expectation that its erstwhile allies, Germany and Japan, would jump in on its side and declare war on the United States; significantly, the declaration of war by the U.S. on December 8, 1941 was only against Japan. Thus, Japan could reasonably have expected to confront the full force of U.S. military might and industry. That they only, fortuitously for them, faced a fraction of total U.S. power and still were utterly defeated shows the depth of their miscalculations.

There was a further element of Japanese strategic miscalculation. Their basic war strategy was to occupy the islands of the Western Pacific and fortify them, creating a fortified perimeter through which the American armed forces would have to penetrate. Japanese fortified island positions indeed proved tough to assault and capture, but U.S. forces only needed to pierce the perimeter, not reduce it. John D. Chappell notes how as the war dragged on and the battle came closer and closer to the U.S. home islands, victories for the U.S. became more and more costly: “As U.S. forces drove closer to Japan, casualties rose. […] Although obviously defeated, the Japanese persisted with suicidal defense at Iwo Jima, Okinawa, and in the Philippines” (Chappell 2). The Japanese had hoped that this would be the norm from the beginning of the inevitable American counteroffensive and that fighting its way west from island to fortified island would ultimately prove too costly for the U.S. However, American strategic doctrine was to pierce the island perimeter and head straight for Japan via “island hopping,” bypassing most fortified Japanese outposts and leaving their garrisons to wither on the vine. This would not have been a viable strategy if the Japanese had had superior airpower (due to the exposed flanks of the advance), but they had lost their air superiority at Midway and were never able to catch up to America’s industrial might after that.

Pearl Harbor did have one consequence that, while having little to do with the outcome of the war, did have an effect on the values of American democracy. In the wave of hysteria that followed the Pearl Harbor attack, ethnic Japanese were rounded up and confined to internment camps for the duration of the war. They were only allowed to take with them what they could pack in suitcases and lived in isolated, miserable enclaves that were little better than concentration camps. Manzanar, in the high deserts of eastern California, was one example. Jerry Stanley reported that “Manzanar was modeled after an army base designed to house single men. It was one mile square and divided into thirty-six blocks with four barracks to a block” (Stanley 41). This camp designed to be a barracks for single men was used to house entire families. It contained no recreational or educational facilities, and communal laundry, water, and dining facilities were inadequate. This was despite the fact that many of these people were U.S. citizens and very, very few of them had committed any covert or overt acts against the United States. Americans were understandably angry about Pearl Harbor, but their anger against their countrymen was misplaced. Notably, no such backlash was ever directed against Americans of German or Italian ancestry; the Japanese were just a bit more “alien” and therefore, it was proper in the eyes of the public to mistreat them.

The anger that the American public felt at the Japanese had another unforeseen consequence. The Manhattan Project, initiated in 1942, was to develop and use an atomic weapon. As per the “Germany first” doctrine, it was meant to be used if necessary on Germany. However, Germany’s collapse in early 1945 meant that by the time the bomb was ready, only Japan remained to use it on. Yet, by 1945, Japan was prostrate and militarily no longer a threat. The Potsdam declaration made by the allies shortly after the German surrender threatened Japan with “total annihilation” if it didn’t surrender. Yet, only the Americans knew that the atomic bomb was almost ready to go. It was nonetheless anticipated that an invasion of the Japanese home islands would be necessary to end the war. Estimates of the cost of that campaign were from 250,000 to 750,000 Allied and up to 20,000,000 Japanese casualties, given the fanatical defense put up by Japanese forces so far. It is interesting to speculate whether this attack would actually have taken place, given its horrific anticipated cost, had the atomic bomb not offered an additional option. However, most historians present this decision as an either-or. The fact remains that the Allies could have simply isolated Japan and slowly destroyed its remaining military capacity through conventional air and submarine warfare, thus compelling its eventual surrender without the need for invasion or atomic attack.

The question, then of why the atomic bomb was used on Japan suggests itself. One possibility is the racial hatred that was a feature of American home front propaganda ever since the Pearl Harbor attack. The Japanese were depicted as hateful, devious, lying savages. Their armed forces’ actual conduct during the war only served to reinforce that perception. And of course, that the Pearl Harbor attack was a sneak attack without a declaration of war had reinforced that perception further still. The Japanese had actually intended to make a formal declaration of war one hour before the attack, but a diplomatic mix-up had delayed that announcement until well after the attack. This was another miscalculation on the part of the Japanese, in that they underestimated the Americans’ fury and hatred toward then that the sneak attack would generate. In this writer’s opinion, that hatred manifested itself in the unjust treatment of the interned Japanese-Americans and culminated in President Truman’s lack of compunction in ordering the incineration of two Japanese cities in atomic fireballs.

The Pearl Harbor attack still lingers in the American consciousness. It was a long time after the war’s end before Americans viewed the Japanese as trustworthy people (the impression of them being “sneaky” lingers to this day, in fact). And of course, the military disaster that followed Japan’s brief string of triumphs devastated the nation and was the cause of the death of much of an entire generation of Japan’s young men. In light of Japan’s prosperity and stability in the postwar period, one wonders just what the county could have accomplished had it not gone down that suicidal path.

Of course, one could take the very long view that Japan’s military dictatorship of 1941 would never have, under its own power, changed into today's’ peaceful, prosperous democracy. When considering what Japan has done since the war, it could be said that they lost the war but won the peace. Japanese autos, electronics, and other consumer goods have dominated American markets for decades. Its business models have inspired other countries worldwide. It has been remarked, facetiously but not without an element of truth, that the best thing that could happen to a country is to lose a war to the United States. Pearl Harbor all but guaranteed that that very thing would happen. So in an ironic way, the Pearl Harbor attack created the future prosperous, world-beating Japan we see today, with its stable, democratic government and robust economy.

Works Cited

Chappell, John David. Before the bomb: How America approached the end of the Pacific war. University Press of Kentucky, 1997.

Stanley, Jerry. I am an American: A true story of Japanese internment. Crown Publishers, 1994.

Whitman, Sylvia. V is for victory: The American Home Front During World War II. Twenty-First Century Books, 1993.

Wohlstetter, Roberta. "Cuba and Pearl Harbor: Hindsight and Foresight." Foreign Affairs 43.4 (1965): 691-707.

Wohlstetter, Roberta. Pearl Harbor: warning and decision. Stanford University Press, 1962.