Attack on Pearl Harbor The attack on Pearl Harbor was a surprise military strike conducted by the Imperial Japanese Navy against the United States naval base at Pearl Harbor , Hawaii , on the morning of December 7 , 1941 ( December 8 in Japan ) . The attack led to the United States ' entry into World War II . The attack was intended as a preventive action in order to keep the U . S . Pacific Fleet from interfering with military actions the Empire of Japan was planning in Southeast Asia against overseas territories of the United Kingdom , the Netherlands , and the United States . There were simultaneous Japanese attacks on the US - held Philippines and on the British Empire in Malaya , Singapore , and Hong Kong . From the standpoint of the defenders , the attack commenced at 7 : 48 a . m . Hawaiian Time . The base was attacked by 353 Japanese fighters , bombers and torpedo planes in two waves , launched from six aircraft carrier s . All eight U . S . Navy battleships were damaged , with four being sunk . Two of these were later raised , and with the remaining four repaired , six battleships returned to service later in the war . The Japanese also sank or damaged three cruiser s , three destroyer s , an anti - aircraft training ship , and one minelayer . 188 U . S . aircraft were destroyed ; 2 , 402 Americans were killed and 1 , 282 wounded . Important base installations such as the power station , shipyard , maintenance , and fuel and torpedo storage facilities , as well as the submarine piers and headquarters building ( also home of the intelligence section ) were not attacked . Japanese losses were light : 29 aircraft and five midget submarine s lost , and 65 servicemen killed or wounded . One Japanese sailor was captured . The attack came as a profound shock to the American people and led directly to the American entry into World War II in both the Pacific and European theaters . The following day ( December 8 ) , the United States declared war on Japan . Domestic support for non - interventionism , which had been strong , disappeared . Clandestine support of Britain ( for example the Neutrality Patrol ) was replaced by active alliance . Subsequent operations by the U . S . prompted Germany and Italy to declare war on the U . S . on December 11 , which was reciprocated by the U . S . the same day . There were numerous historical precedents for unannounced military action by Japan . However , the lack of any formal warning , particularly while negotiations were still apparently ongoing , led President Franklin D . Roosevelt to proclaim December 7 , 1941 , " a date which will live in infamy " . Background to conflict . Anticipating war . The attack on Pearl Harbor was intended to neutralize the U . S . Pacific Fleet , and hence protect Japan ' s advance into Malaya and the Dutch East Indies , where it sought access to natural resources such as oil and rubber . War between Japan and the United States had been a possibility of which each nation had been aware ( and developed contingency plans for ) since the 1920s , though tensions did not begin to grow seriously until Japan ' s 1931 invasion of Manchuria . Over the next decade , Japan continued to expand into China , leading to all - out war between those countries in 1937 . Japan spent considerable effort trying to isolate China and achieve sufficient resource independence to attain victory on the mainland ; the " Southern Operation " was designed to assist these efforts . From December 1937 , events such as the Japanese attack on the USS " Panay " and the Nanking Massacre ( more than 200 , 000 killed in indiscriminate massacres ) swung public opinion in the West sharply against Japan and increased Western fear of Japanese expansion , which prompted the United States , the United Kingdom , and France to provide loan assistance for war supply contracts to the Republic of China . In 1940 , Japan invaded French Indochina in an effort to control supplies reaching China . The United States halted shipments of airplanes , parts , machine tool s , and aviation gasoline to Japan ; this was perceived by Japan as an unfriendly act . The U . S . did not stop oil exports to Japan at that time in part because prevailing sentiment in Washington was that such an action would be an extreme step , given Japanese dependence on U . S . oil , and likely to be considered a provocation by Japan . Early in 1941 , President Franklin D . Roosevelt moved the Pacific Fleet to Hawaii from its previous base in San Diego and ordered a military buildup in the Philippines in the hope of discouraging Japanese aggression in the Far East . Because the Japanese high command was ( mistakenly ) certain any attack on Britain ' s Southeast Asian colonies would bring the U . S . into the war , a devastating preventive strike appeared to be the only way to avoid U . S . naval interference . An invasion of the Philippines was also considered to be necessary by Japanese war planners . The U . S . War Plan Orange had envisioned defending the Philippines with a 40 , 000 man elite force . This was opposed by Douglas MacArthur , who felt that he would need a force ten times that size , and was never implemented . By 1941 , U . S . planners anticipated abandonment of the Philippines at the outbreak of war and orders to that effect were given in late 1941 to Admiral Thomas Hart , commander of the Asiatic Fleet . The U . S . ceased oil exports to Japan in July 1941 , following Japanese expansion into French Indochina after the fall of France , in part because of new American restrictions on domestic oil consumption . This in turn caused the Japanese to proceed with plans to take the Dutch East Indies , an oil - rich territory . On 17 August Roosevelt warned Japan that the U . S . was prepared to take any and all steps against Japan if it attacked " neighboring countries " . The Japanese were faced with the option of either withdrawing from China and losing face or seizing and securing new sources of raw materials in the resource - rich , European - controlled colonies of Southeast Asia . Japan and the U . S . engaged in negotiations during the course of 1941 in an effort to improve relations . During these negotiations Japan offered to withdraw from most of China and Indochina when peace was made with the Nationalist government , adopt an independent interpretation of the Tripartite Pact , and to not discriminate in trade provided all other countries reciprocated . These proposals were rejected by Washington . Japan ' s final proposal , on 20 November , offered to withdraw their forces from southern Indochina and not to launch any attacks in southeast Asia provided that the U . S . , Britain , and the Netherlands ceased aiding China and lifted their sanctions against Japan . The American counterproposal of 26 November ( the Hull note ) required Japan to evacuate all of China without conditions and conclude non - aggression pacts with Pacific powers . Preliminary planning for an attack on Pearl Harbor to protect the move into the " Southern Resource Area " ( the Japanese term for the Dutch East Indies and Southeast Asia generally ) had begun very early in 1941 under the auspices of Admiral Isoroku Yamamoto , then commanding Japan ' s Combined Fleet . He won assent to formal planning and training for an attack from the Imperial Japanese Navy General Staff only after much contention with Naval Headquarters , including a threat to resign his command . Full - scale planning was underway by early spring 1941 , primarily by Captain Minoru Genda and Deputy Chief of Staff , Captain Kameto Kurojima . Japanese planning staff studied the 1940 British air attack on the Italian fleet at Taranto intensively . It was of great use to them when planning their attack on U . S . naval forces in Pearl Harbor . Over the next several months , pilots trained , equipment was adapted , and intelligence collected . Despite these preparations , the attack plan was not approved by Emperor Hirohito until November 5 , after the third of four Imperial Conferences called to consider the matter . Final authorization was not given by the emperor until December 1 , after a majority of Japanese leaders advised him the " Hull Note " would " destroy the fruits of the China incident , endanger Manchukuo and undermine Japanese control of Korea . " By late 1941 , many observers believed that hostilities between the U . S . and Japan were imminent . A Gallup poll just before the attack on Pearl Harbor found that 52 % of Americans expected war with Japan , 27 % did not expect war , and 21 % had no opinion . While U . S . Pacific bases and facilities had been placed on alert on multiple occasions , U . S . officials doubted Pearl Harbor would be the first target . They expected the Philippines to be attacked first . This presumption was due to the threat that the air bases throughout the country and the naval base at Manila posed to sea lanes , as well as the shipment of supplies to Japan from territory to the south . They also incorrectly believed that Japan was not capable of mounting more than one major naval operation at a time . Objectives . The attack had several major aims . First , it intended to destroy important American fleet units , thereby preventing the Pacific Fleet from interfering with Japanese conquest of the Dutch East Indies and Malaya . Second , it was hoped to buy time for Japan to consolidate its position and increase its naval strength before shipbuilding authorized by the 1940 Vinson - Walsh Act erased any chance of victory . Finally , it was meant to deliver a severe blow to American morale , one which would discourage Americans from committing to a war extending into the western Pacific Ocean and Dutch East Indies . To maximize the effect on morale , battleships were chosen as the main targets , since they were the prestige ships of any navy at the time . The overall intention was to enable Japan to conquer Southeast Asia without interference . Striking the Pacific Fleet at anchor in Pearl Harbor carried two distinct disadvantages : the targeted ships would be in very shallow water , so it would be relatively easy to salvage and possibly repair them ; and most of the crews would survive the attack , since many would be on shore leave or would be rescued from the harbor . A further important disadvantage — this of timing , and known to the Japanese — was the absence from Pearl Harbor of all three of the U . S . Pacific Fleet ' s aircraft carriers ( , , and ) . Ironically , the IJN top command was so imbued with Admiral Mahan ' s " decisive battle " doctrine — especially that of destroying the maximum number of battleships — that , despite these concerns , Yamamoto decided to press ahead . Japanese confidence in their ability to achieve a short , victorious war also meant other targets in the harbor , especially the navy yard , oil tank farms , and submarine base , could safely be ignored , since — by their thinking — the war would be over before the influence of these facilities would be felt . Approach and attack . On November 26 , 1941 , a Japanese task force ( the Striking Force ) of six aircraft carriers ( " Akagi " , " Kaga " , " Sōryū " , " Hiryū " , " Shōkaku " , and " Zuikaku " ) departed northern Japan " en route " to a position northwest of Hawaii , intending to launch its aircraft to attack Pearl Harbor . In all , 408 aircraft were intended to be used : 360 for the two attack waves , 48 on defensive combat air patrol ( CAP ) , including nine fighters from the first wave . The first wave was to be the primary attack , while the second wave was to finish whatever tasks remained . The first wave carried most of the weapons to attack capital ships , mainly specially adapted Type 91 aerial torpedo es which were designed with an anti - roll mechanism and a rudder extension that let them operate in shallow water . The aircrews were ordered to select the highest value targets ( battleships and aircraft carrier s ) or , if these were not present , any other high value ships ( cruisers and destroyers ) . Dive bomber s were to attack ground targets . Fighters were ordered to strafe and destroy as many parked aircraft as possible to ensure they did not get into the air to intercept the bombers , especially in the first wave . When the fighters ' fuel got low they were to refuel at the aircraft carriers and return to combat . Fighters were to serve CAP duties where needed , especially over US airfields . Before the attack commenced , two reconnaissance aircraft launched from cruisers were sent to scout over Oahu and report on enemy fleet composition and location . Another four scout planes patrolled the area between the Japanese carrier force ( the Kido Butai ) and Niihau , to detect any counterattack . Submarines . Fleet submarines " I - 16 " , " I - 18 " , " I - 20 " , " I - 22 " , and " I - 24 " each embarked a Type A midget submarine for transport to the waters off Oahu . The five I - boats left Kure Naval District on November 25 , 1941 , coming to off the harbor mouth and launched their charges at about 01 : 00 on December 7 . At 03 : 42 Hawaiian Time , the minesweeper " Condor " spotted a midget submarine periscope southwest of the Pearl Harbor entrance buoy and alerted the destroyer " Ward " . The midget may have entered Pearl Harbor . However , " Ward " sank another midget submarine at 06 : 37 in the first American shots in the Pacific Theater . A midget submarine on the north side of Ford Island missed the seaplane tender " Curtiss " with her first torpedo and missed the attacking destroyer " Monaghan " with her other one before being sunk by " Monaghan " at 08 : 43 . A third midget submarine grounded twice , once outside the harbor entrance and again on the east side of Oahu , where it was captured on December 8 . Ensign Kazuo Sakamaki swam ashore and was captured by Hawaii National Guard Corporal David Akui , becoming the first Japanese prisoner of war . A fourth had been damaged by a depth charge attack and was abandoned by its crew before it could fire its torpedoes . A United States Naval Institute analysis of photographs from the attack , conducted in 1999 , indicated a midget submarine may have successfully fired a torpedo into " West Virginia " . Japanese forces received a radio message from a midget submarine at 00 : 41 December 8 claiming damage to one or more large war vessels inside Pearl Harbor . The submarine ' s final disposition is unknown , but she did not return to her " mother " sub . On December 7 , 2009 , the " Los Angeles Times " reported there is circumstantial evidence three pieces of a submarine discovered south of Pearl Harbor between 1994 and 2001 could be the missing submarine . It also reported there is strong circumstantial evidence the submarine fired two torpedoes at Battleship Row . The debris was dumped outside the harbor as part of an effort to conceal the West Loch Disaster , a 1944 ammunition explosion that destroyed six tank landing ship s preparing for Operation Forager . Japanese declaration of war . The attack took place before any formal declaration of war was made by Japan , but this was not Admiral Yamamoto ' s intention . He originally stipulated that the attack should not commence until thirty minutes after Japan had informed the United States that peace negotiations were at an end . The Japanese tried to uphold the conventions of war while still achieving surprise , but the attack began before the notice could be delivered . Tokyo transmitted the 5 , 000 - word notification ( commonly called the " 14 - Part Message " ) in two blocks to the Japanese Embassy in Washington , but transcribing the message took too long for the Japanese ambassador to deliver it in time . ( In fact , U . S . code breakers had already deciphered and translated most of the message hours before he was scheduled to deliver it . ) The final part of the " 14 Part Message " is sometimes described as a declaration of war . While it neither declared war nor severed diplomatic relations , it was viewed by a number of senior U . S government and military officials as a very strong indicator that negotiations were likely to be terminated and that war might break out at any moment . A declaration of war was printed on the front page of Japan ' s newspapers in the evening edition of December 8 , but not delivered to the U . S . government until the day after the attack . For decades , conventional wisdom held that Japan attacked without any official warning of a break in relations only because of accidents and bumbling that delayed the delivery of a document hinting at war to Washington . In 1999 , however , Takeo Iguchi , a professor of law and international relations at International Christian University in Tokyo , discovered documents that pointed to a vigorous debate inside the government over how , and indeed whether , to notify Washington of Japan ' s intention to break off negotiations and start a war , including a December 7 entry in the war diary saying , " our deceptive diplomacy is steadily proceeding toward success . " Of this , Iguchi said , " The diary shows that the army and navy did not want to give any proper declaration of war , or indeed prior notice even of the termination of negotiations . . . and they clearly prevailed . " First wave composition . The first attack wave of 183 planes was launched north of Oahu , led by Commander Mitsuo Fuchida . It included : Six planes failed to launch due to technical difficulties . As the first wave approached Oahu , it was detected by the U . S . Army SCR - 270 radar at Opana Point near the island ' s northern tip . This post had been in training mode for months , but was not yet operational . Although the operators , Privates George Elliot Jr . and Joseph Lockard , reported a target , a newly assigned officer at the thinly manned Intercept Center , Lieutenant Kermit A . Tyler , presumed it was the scheduled arrival of six B - 17 bombers . The direction from which the aircraft were coming was close ( only a few degrees separated the two inbound courses ) , while the operators had never seen a formation as large on radar ; they neglected to tell Tyler of its size , while Tyler , for security reasons , could not tell them the B - 17s were due ( even though it was widely known ) . As the first wave planes approached Oahu , they encountered and shot down several U . S . aircraft . At least one of these radioed a somewhat incoherent warning . Other warnings from ships off the harbor entrance were still being processed or awaiting confirmation when the attacking planes began bombing and strafing . Nevertheless , it is not clear any warnings would have had much effect even if they had been interpreted correctly and much more promptly . The results the Japanese achieved in the Philippines were essentially the same as at Pearl Harbor , though MacArthur had almost nine hours warning that the Japanese had already attacked at Pearl . The air portion of the attack on Pearl Harbor began at 7 : 48 a . m . Hawaiian Time ( 3 : 18 a . m . December 8 Japanese Standard Time , as kept by ships of the " Kido Butai " ) , with the attack on Kaneohe . A total of 353 Japanese planes in two waves reached Oahu . Slow , vulnerable torpedo bombers led the first wave , exploiting the first moments of surprise to attack the most important ships present ( the battleships ) , while dive bombers attacked U . S . air bases across Oahu , starting with Hickam Field , the largest , and Wheeler Field , the main U . S . Army Air Force fighter base . The 171 planes in the second wave attacked the Air Corps ' Bellows Field near Kaneohe on the windward side of the island , and Ford Island . The only aerial opposition came from a handful of P - 36 Hawk s , P - 40 Warhawk s and some SBD Dauntless dive bombers from the carrier USS " Enterprise " . Men aboard U . S . ships awoke to the sounds of alarms , bombs exploding , and gunfire , prompting bleary - eyed men to dress as they ran to General Quarters stations . ( The famous message , " Air raid Pearl Harbor . This is not drill . " , was sent from the headquarters of Patrol Wing Two , the first senior Hawaiian command to respond . ) The defenders were very unprepared . Ammunition lockers were locked , aircraft parked wingtip to wingtip in the open to deter sabotage , guns unmanned ( none of the Navy ' s 5 " / 38s , only a quarter of its machine gun s , and only four of 31 Army batteries got in action ) . Despite this low alert status , many American military personnel responded effectively during the battle . Ensign Joe Taussig , Jr . , the only commissioned officer aboard USS " Nevada " , got the ship underway during the attack but lost a leg . The ship was beached in the harbor by the Senior Quartermaster . One of the destroyers , USS " Aylwin " , got underway with only four officers aboard , all ensigns , none with more than a year ' s sea duty ; she operated at sea for 36 hours before her commanding officer managed to get back aboard . Captain Mervyn Bennion , commanding USS " West Virginia " , led his men until he was cut down by fragments from a bomb which hit USS " Tennessee " , moored alongside . Second wave composition . The second wave consisted of 171 planes : 54 B5Ns , 81 D3As , and 36 A6Ms , commanded by Lieutenant - Commander Shigekazu Shimazaki . Four planes failed to launch because of technical difficulties . This wave and its targets comprised : The second wave was divided into three groups . One was tasked to attack Kāneohe , the rest Pearl Harbor proper . The separate sections arrived at the attack point almost simultaneously from several directions . American casualties and damages . Ninety minutes after it began , the attack was over , as 2 , 386 Americans died ( 48 - 68 were civilians , most killed by unexploded American anti - aircraft shells landing in civilian areas ) , a further 1 , 139 wounded . Eighteen ships were sunk or run aground , including five battleships . Of the American fatalities , nearly half of the total ( 1 , 177 ) were due to the explosion of " Arizona " ' s forward magazine after it was hit by a modified 40 cm ( 16 in . ) shell . Already damaged by a torpedo and on fire amidships , " Nevada " attempted to exit the harbor . She was targeted by many Japanese bombers as she got under way and sustained more hits from 250 lb ( 113 kg ) bombs , which started further fires . She was deliberately beached to avoid blocking the harbor entrance . " California " was hit by two bombs and two torpedoes . The crew might have kept her afloat , but were ordered to abandon ship just as they were raising power for the pumps . Burning oil from " Arizona " and " West Virginia " drifted down on her , and probably made the situation look worse than it was . The disarmed target ship " Utah " was holed twice by torpedoes . " West Virginia " was hit by seven torpedoes , the seventh tearing away her rudder . " Oklahoma " was hit by four torpedoes , the last two above her belt armor , which caused her to capsize . " Maryland " was hit by two of the converted 40 cm shells , but neither caused serious damage . Although the Japanese concentrated on battleships ( the largest vessels present ) , they did not ignore other targets . The light cruiser " Helena " was torpedoed , and the concussion from the blast capsized the neighboring minelayer " Oglala " . Two destroyers in dry dock , " Cassin " and " Downes " were destroyed when bombs penetrated their fuel bunker s . The leaking fuel caught fire ; flooding the dry dock in an effort to fight fire made the burning oil rise , and both were burned out . " Cassin " slipped from her keel blocks and rolled against " Downes " . The light cruiser " Raleigh " was holed by a torpedo . The light cruiser " Honolulu " was damaged but remained in service . The repair vessel " Vestal " , moored alongside " Arizona " , was heavily damaged and beached . The seaplane tender " Curtiss " was also damaged . The destroyer " Shaw " was badly damaged when two bombs penetrated her forward magazine . Of the 402 American aircraft in Hawaii , 188 were destroyed and 159 damaged , 155 of them on the ground . Almost none was actually ready to take off to defend the base . Eight Army Air Corps pilots managed to get airborne during the battle and six were credited with downing at least one Japanese aircraft during the attack , 1st Lt . Lewis M . Sanders , 2nd Lt . Philip M . Rasmussen , 2nd Lt . Kenneth M . Taylor , 2nd Lt . George S . Welch , 2nd Lt . Harry W . Brown , and 2nd Lt . Gordon H . Sterling Jr . Sterling was shot down by Lt . Fujita over Kaneohe Bay and is listed as Body Not Recovered ( not Missing In Action ) . Johnny Dains was killed by friendly fire returning from a victory over Kaawa . Of 33 PBY s in Hawaii , 24 were destroyed , and six others damaged beyond repair . ( The three on patrol returned undamaged . ) Friendly fire brought down some U . S . planes on top of that , including five from an inbound flight from " Enterprise " . Japanese attacks on barracks killed additional personnel . Fifty - five Japanese airmen and nine submariners were killed in the action , and one was captured . Of Japan ' s 414 available planes , 29 were lost during the battle ( nine in the first attack wave , 20 in the second ) , with another 74 damaged by antiaircraft fire from the ground . Possible third wave . Several Japanese junior officers , including Mitsuo Fuchida and Minoru Genda , the chief architect of the attack , urged Nagumo to carry out a third strike in order to destroy as much of Pearl Harbor ' s fuel and torpedo storage , maintenance , and dry dock facilities as possible ; and the captains of the other five carriers in the formation reported they were willing and ready to carry out a third strike . Military historians have suggested the destruction of these would have hampered the U . S . Pacific Fleet far more seriously than loss of its battleships . If they had been wiped out , " serious [ American ] operations in the Pacific would have been postponed for more than a year " ; according to American Admiral Chester Nimitz , later Commander in Chief of the Pacific Fleet , " it would have prolonged the war another two years . " Nagumo , however , decided to withdraw for several reasons : At a conference aboard " Yamato " the following morning , Yamamoto initially supported Nagumo . In retrospect , sparing the vital dockyards , maintenance shops , and oil depots meant the U . S . could respond relatively quickly to Japanese activities in the Pacific . Yamamoto later regretted Nagumo ' s decision to withdraw and categorically stated it had been a great mistake not to order a third strike . Photographs . The first aerial photographs of the attack on Pearl Harbor were taken by Lee Embree , who was aboard a Boeing B - 17 Flying Fortress " en route " from Hamilton Field , California , to the Philippines . Lee ' s 38th Reconnaissance Squadron had scheduled a refueling stop at Hickam Field at the time of the attack . Salvage . After a systematic search for survivors , formal salvage operations began . Captain Homer N . Wallin , Material Officer for Commander , Battle Force , U . S . Pacific Fleet , was immediately ordered to lead salvage operations . " Within a short time I was relieved of all other duties and ordered to full time work as Fleet Salvage Officer " . Around Pearl Harbor , divers from the Navy ( shore and tenders ) , the Naval Shipyard , and civilian contractors ( Pacific Bridge and others ) began work on the ships that could be refloated . They patched holes , cleared debris , and pumped water out of ships . Navy divers worked inside the damaged ships . Within six months , five battleships and two cruisers were patched or refloated so they could be sent to shipyards in Pearl Harbor and on the mainland for extensive repair . Intensive salvage operations continued for another year , a total of some 20 , 000 man - hours under water . " Oklahoma " , while successfully raised , was never repaired , and capsized while under tow to the mainland in 1947 . " Arizona " and the target ship " Utah " were too heavily damaged for salvage , though much of their armament and equipment was removed and put to use aboard other vessels . Today , the two hulks remain where they were sunk , with " Arizona " becoming a war memorial . Aftermath . In the wake of the attack , 15 Medals of Honor , 51 Navy Cross es , 53 Silver Star s , four Navy and Marine Corps Medal s , one Distinguished Flying Cross , four Distinguished Service Cross es , one Distinguished Service Medal , and three Bronze Star Medal s were awarded to the American servicemen who distinguished themselves in combat at Pearl Harbor . Additionally , a special military award , the Pearl Harbor Commemorative Medal , was later authorized for all military veterans of the attack . The day after the attack , Roosevelt delivered his famous Infamy Speech to a Joint Session of Congress , calling for a formal declaration of war on the Empire of Japan . Congress obliged his request less than an hour later . On December 11 Germany and Italy , honoring their commitments under the Tripartite Pact , declared war on the United States . The Tripartite Pact was an earlier agreement between Germany , Italy and Japan which had the principal objective of limiting U . S . intervention in any conflicts involving the three nations . The United States Congress issued a declaration of war against Germany and Italy later that same day . Britain actually declared war on Japan nine hours before the US did , partially due to Japanese attacks on Malaya , Singapore and Hong Kong , and partially due to Winston Churchill ' s promise to declare war " within the hour " of a Japanese attack on the United States . The attack was an initial shock to all the Allies in the Pacific Theater . Further losses compounded the alarming setback . Japan attacked the Philippines hours later ( because of the time difference , it was December 8 in the Philippines ) . Only three days after the attack on Pearl Harbor , the " Prince of Wales " and " Repulse " were sunk off the coast of Malaya , causing British Prime Minister Winston Churchill later to recollect " In all the war I never received a more direct shock . As I turned and twisted in bed the full horror of the news sank in upon me . There were no British or American capital ships in the Indian Ocean or the Pacific except the American survivors of Pearl Harbor who were hastening back to California . Over this vast expanse of waters Japan was supreme and we everywhere were weak and naked " . Throughout the war , Pearl Harbor was frequently used in American propaganda . One further consequence of the attacks on Pearl Harbor and its aftermath ( notably the Niihau Incident ) was that Japanese American residents and citizens were relocated to nearby Japanese - American internment camps . Within hours of the attack , hundreds of Japanese American leaders were rounded up and brought to high - security camps such as Sand Island at the mouth of Honolulu harbor and Kilauea Military Camp on the island of Hawaii . Later , over 110 , 000 Japanese Americans , including United States citizens , were removed from their homes and transferred to internment camps in California , Idaho , Utah , Arizona , Wyoming , Colorado , and Arkansas . Niihau Incident . The Japanese planners had determined that some means of rescuing fliers whose aircraft were too badly damaged to return to the carriers was required . The island of Niihau , only 30 minutes flying time from Pearl Harbor , was designated as the rescue point . The Zero flown by Petty Officer Shigenori Nishikaichi of Hiryu was damaged in the attack on Wheeler , and he flew to the rescue point on Niihau . The aircraft was further damaged on landing . Nishikaichi was helped from the wreckage by one of the native Hawaiian inhabitants , who , aware of the tension between the United States and Japan , took the pilot ' s maps and other documents . The island ' s residents had no telephones or radio and were completely unaware of the attack on Pearl Harbor . Nishikaichi enlisted the support of two Japanese - American residents in an attempt to recover the documents . During the ensuing struggles , Nishikaichi was killed , one collaborator committed suicide , and his wife was sent to prison . The ease with which the local ethnic Japanese residents apparently went to the assistance of Nishikaichi was a source of concern for many , and tended to support those who believed that local Japanese could not be trusted . Strategic implications . Admiral Hara Tadaichi summed up the Japanese result by saying , " We won a great tactical victory at Pearl Harbor and thereby lost the war . " While the attack accomplished its intended objective , it turned out to be largely unnecessary . Unbeknownst to Yamamoto , who conceived the original plan , the U . S . Navy had decided as far back as 1935 to abandon ' charging ' across the Pacific towards the Philippines in response to an outbreak of war ( in keeping with the evolution of Plan Orange ) . The U . S . instead adopted " Plan Dog " in 1940 , which emphasized keeping the IJN out of the eastern Pacific and away from the shipping lanes to Australia while the U . S . concentrated on defeating Nazi Germany . Fortunately for the United States , the American aircraft carriers were untouched by the Japanese attack , otherwise the Pacific Fleet ' s ability to conduct offensive operations would have been crippled for a year or more ( given no diversions from the Atlantic Fleet ) . As it was , the elimination of the battleships left the U . S . Navy with no choice but to rely on its aircraft carriers and submarines — the very weapons with which the U . S . Navy halted and eventually reversed the Japanese advance . While six of the eight battleships were repaired and returned to service , their relatively low speed limited their deployment , and they served mainly in shore bombardment roles ( their only major action being the Battle of Surigao Strait ) . A major flaw of Japanese strategic thinking was a belief that the ultimate Pacific battle would be fought by battleships , in keeping with the doctrine of Captain Alfred Thayer Mahan . As a result , Yamamoto ( and his successors ) hoarded battleships for a " decisive battle " that never happened . The Japanese confidence in their ability to achieve a short , victorious war meant that they neglected the navy repair yards , oil tank farms , submarine base , and old headquarters building . All of these targets were omitted from Genda ' s list , yet they proved more important than any battleship to the American war efforts in the Pacific . The survival of the repair shops and fuel depots allowed Pearl Harbor to maintain logistical support to the US Navy ' s operations , such as the Battles of Coral Sea and Midway . It was submarines that immobilized the Imperial Japanese Navy ' s heavy ships and brought Japan ' s economy to a virtual standstill by crippling the transportation of oil and raw materials : import of raw materials was down by half what it had been at the end of 1942 , " to a disastrous ten million tons " , while oil import " was almost completely stopped " . Lastly , the basement of the Old Administration Building was the home of the cryptanalytic unit which contributed significantly to the Midway ambush and the Submarine Force ' s success . Present day . Today , the USS Arizona Memorial on the island of Oahu honors the lives lost on the day of the attack . Visitors to the memorial reach it via boats from the naval base at Pearl Harbor . Alfred Preis is the architect responsible for the memorial ' s design . The structure has a sagging center and its ends strong and vigorous . It commemorates " initial defeat and ultimate victory " of all lives lost on December 7 , 1941 . Although December 7 is known as Pearl Harbor Day , it is not considered a federal holiday in the United States . The nation does however , continue to pay homage remembering the thousands injured and killed when attacked by the Japanese in 1941 . Schools and other establishments across the country respectfully lower the American flag to half - staff . Media . Films set at or around the bombing of Pearl Harbor include :