Attack on Pearl Harbor | World War II

The raid on Pearl Harbor was a surprise military strike on the United States by the Imperial Japanese Navy Air Service on the marine base at Pearl Harbor in Honolulu, Territory of Hawaii, immediately before 08:00 on Sunday, December 7, 1941. The US was a neutral country, but the attack prompted it to enter World War II the next day. During its planning, the Japanese military leadership referred to the operation as the Hawaii Operation, Operation AI, and Operation Z.

The strike was designed to deter the United States Pacific Fleet from interfering with Japan's planned military operations in Southeast Asia against the United Kingdom, the Netherlands, and US overseas territories. Accordingly, Japan launched coordinated attacks on the US-held Philippines, Guam, and Wake Island and the British Empire in Malaya, Singapore, and Hong Kong over seven hours.

At 7:48 a.m. Hawaiian Time, the attack began (18:18 GMT). 353 Imperial Japanese aircraft counting fighters, level and dive bombers, and torpedo bombers deployed from six aircraft carriers assaulted the facility in two waves. All eight US Navy battleships present were damaged, four of them sinking. All but the USS Arizona were later elevated, and six were recommissioned and served in the war. The Japanese also sunk or damaged three cruisers, three destroyers, an antiaircraft training ship, and one minelayer. A total of 188 American planes were shot down, killing 2,403 people and injuring 1,178 more. The power plant, dry dock, shipyard, maintenance, fuel and torpedo storage facilities, as well as the submarine piers and headquarters building (which also houses the intelligence unit), were not targeted. The Japanese suffered only minor losses, with 29 planes and five midget submarines lost, and 64 troops dead. One of the submarines' commanding officers, Kazuo Sakamaki, was apprehended.

Later that day (December 8 in Tokyo), Japan declared war on the United States and the British Empire, but the declarations were not delivered until the next day. After realizing that their territory had also been attacked, the British government declared war on Japan, and the United States Congress declared war on Japan the next day (December 8). Germany and Italy announced war on the United States on December 11, despite having no formal responsibility under the Tripartite Pact with Japan. The United States replied by saying the war on Germany and Italy. There were numerous historical precedents for Japan's surprise military action. Still, the lack of any formal warning, especially while peace talks appeared to be progressing, led President Franklin D. Roosevelt to declare December 7, 1941, "a date that will live in infamy." The attack on Pearl Harbor was eventually declared a war crime in the Tokyo Trials because it occurred without a declaration of war or express warning.

Diplomatic Background

Since the 1920s, the conflict between Japan and the United States had been a possibility that both countries had anticipated and planned. Since the late 1890s, Japan had been suspicious of American territorial and military expansion in the Pacific and Asia, including the annexation of islands like Hawaii and the Philippines that they considered close to or inside their sphere of influence. Even though Japan had begun to pursue a hostile posture against the United States following the rejection of the Racial Equality Proposal, the two countries' relationship remained cordial enough for them to continue trading partners. Tensions did not rise until Japan invaded Manchuria in 1931. Then, Japan advanced into China throughout the next decade, resulting in the Second Sino-Japanese War in 1937. Japan made a concerted attempt to isolate China and collect sufficient independent resources to achieve victory on the mainland. The "Southern Operation" was created to aid in these endeavours.

Events such as the Japanese raid on the USS Panay, the Allison occurrence, and the Nanking Massacre moved Western public opinion significantly against Japan beginning in December 1937. The US planned a united action with the British to blockade Japan, but it was unsuccessful. Following President Franklin D. Roosevelt's request, American corporations stopped supplying Japan with military hardware in 1938. Invading French Indochina in 1940, Japan attempted to impede the flow of goods to China. The US blocked exports of airplanes, components, machine tools, and aviation gasoline to Japan, which the latter saw as a hostile act. However, the United States did not halt oil deliveries, owing to a widespread belief in Washington that such an act would be seen as an extreme provocation given Japan's reliance on American oil.

President Franklin D. Roosevelt relocated the Pacific Fleet from San Diego to Hawaii in the mid-1940s. He also authorized a military buildup in the Philippines to deter Japanese invasion in the region. Because the Japanese high command believed (incorrectly) that attacking the United Kingdom's Southeast Asian colonies, particularly Singapore, would draw the United States into the war, a deadly preventative strike appeared to be the only way to avoid American naval participation. Japanese war planners also felt an invasion of the Philippines to be necessary. The United States' War Plan Orange called for a 40,000-man elite force to defend the Philippines; this option was never executed due to objections from Douglas MacArthur, who believed he would need a power ten times that size. By 1941, American planners expected the Philippines would be abandoned at war. Admiral Thomas C. Hart, commander-in-chief of the Asiatic Fleet, received orders to such effect later that year. Following the capture of French Indochina after the fall of France, the United States eventually stopped exporting oil to Japan in July 1941, partly due to new American limitations on domestic oil consumption.

Due to this decision, Japan proceeded with preparations to capture the oil-rich Dutch East Indies. On August 17, Roosevelt cautioned Japan that America would respond if "neighbouring countries" were attacked. The Japanese were presented with a choice: withdraw from China and risk losing face, or capture fresh raw material supplies in Southeast Asia's resource-rich European possessions.

In 1941, Japan and the United States had talks to strengthen relations. After reaching an agreement with the Nationalist administration, Japan offered to withdraw from most of China and Indochina. It also recommended using its interpretation of the Tripartite Pact and refraining from trade discrimination if all other countries did the same. The White House turned down these suggestions. The Japanese Prime Minister Konoye then requested to meet with Roosevelt, but Roosevelt refused to strike a deal first. The US envoy to Japan pressed Roosevelt to accept the conference several times, saying it was the only way to keep the conciliatory Konoye cabinet in power and maintain Pacific peace. His proposal, however, went unheeded. When the Japanese military refused to remove all troops from China, the Konoye administration fell apart the following month.

Japan's final proposal, delivered on November 20, proposed that the US, UK, and Netherlands supply one million US gallons of aviation fuel, lift their sanctions against Japan, and stop aid to China in exchange for Japan withdrawing from southern Indochina and refraining from attacks in Southeast Asia. The Hull note, an American counter-proposal dated November 26 (November 27 in Japan), demanded that Japan unconditionally withdraw from China and sign non-aggression pacts with Pacific states. However, the Japanese task force departed port for Pearl Harbor on November 26, before the note was delivered.

The strike was intended to deter the US Pacific Fleet from interfering with Japan's planned military efforts in Southeast Asia against British, Dutch, and US foreign territories. Accordingly, Japan launched coordinated attacks on the US-held Philippines, Guam, and Wake Island and the British Empire in Malaya, Singapore, and Hong Kong over seven hours. Furthermore, the Japanese viewed it as a preemptive strike "before the oil gauge ran out." Admiral Isoroku Yamamoto, then ordering Japan's Combined Fleet, had begun preliminary preparation for an attack on Pearl Harbor to protect the march into the "Southern Resource Area" (the Japanese designation for the Dutch East Indies and Southeast Asia in general) fairly early in 1941. The Imperial Japanese Navy General Staff finally agreed to official planning and preparation for an attack after extensive wrangling with Naval Headquarters, including a threat to resign his command.

Military Planning

By early spring 1941, full-scale preparation had begun, led by Rear Admiral Rynosuke Kusaka, with help from Captain Minoru Genda and Yamamoto's Deputy Chief of Staff, Captain Kameto Kuroshima. The strategists spent a lot of time studying the British air attack on the Italian fleet at Taranto in 1940.

Pilots were taught, equipment was altered, and intelligence was gathered over the next few months. Despite these preparations, Emperor Hirohito did not accept the invasion plan until November 5, following the third of four Imperial Conferences convened to discuss the issue. Finally, after a majority of Japanese leaders warned him that the "Hull Note" would "destroy the fruits of the China incident, threaten Manchukuo, and undermine Japanese rule of Korea," the emperor gave final approval on December 1.

By late 1941, many observers feared that war between the United States and Japan was the horizon. Just before the invasion on Pearl Harbor, a Gallup poll found that 52 per cent of Americans expected war with Japan, 27 per cent did not, and 21 per cent were undecided. Even though US Pacific bases and infrastructure had been placed on high alert numerous times, US officials doubted Pearl Harbor would be the initial target; instead, the Philippines were expected to be attacked first. This assumption was based on the threat the country's airbases and the navy base in Manila posed to sea passages and supplies to Japan from territories to the south. They also assumed, mistakenly, that Japan could not conduct more than one major naval campaign at a time.

Objectives

The Japanese onslaught had several key goals. First, it aimed to destroy critical American fleet units, preventing the Pacific Fleet from interfering with Japan's attack of the Dutch East Indies and Malaya and allowing Japan to overrun Southeast Asia unhindered. Second, it was anticipated to provide Time for Japan to consolidate its position and strengthen its naval forces before the 1940 Vinson-Walsh Act, which enabled shipbuilding, eliminated any possibility of success. Third, battleships were chosen as the principal targets to strike America's ability to organize its forces in the Pacific, as they were the prestige ships of any navy at the time. Finally, it was believed that the attack would lower American morale enough that the US administration would abandon its anti-Japanese demands and seek a peaceful solution with Japan.

Striking the Pacific Fleet at Pearl Harbor had two clear disadvantages: the targeted ships would be in low water, making them relatively easy to salvage and possibly repair. Moreover, the majority of the sailors would escape the attack because many would-bes on shore leave or are rescued from the harbour. Another significant disadvantage was the absence from Pearl Harbor of all three aircraft carriers of the United States Pacific Fleet (Enterprise, Lexington, and Saratoga). Nevertheless, Admiral Mahan's "decisive combat" doctrine, particularly the goal of destroying the most significant number of battleships, embraced the IJN's top brass. Despite these reservations, Yamamoto chose to go ahead with the project. Other targets in the port, including the navy yard, oil tank farms, and submarine station, were neglected since, in their minds, the war would be over before the effect of these amenities would be felt.

A Japanese task force on 26 November 1941, consisting of six aircraft carriers (Akagi, Kaga, Sry, Hiry, Shkaku, and Zuikaku) departed Hittokapu Bay on Kasatka Island in the Kuril Islands en route to a location northwest of Hawaii, anticipating to launch its 408 aircraft to raid Pearl Harbor: 360 for the two invasion waves and 48 for defensive combat air patrol (CAP), including nine fighters. The first wave was supposed to be the main assault, while the second wave was supposed to go after carriers first, cruisers second, and battleships third.

The first wave carried most of the armaments used to strike capital ships, namely Type 91 aerial torpedoes with an anti-roll mechanism and a rudder extension that allowed them to operate in shallow water. If these were not present, the aircrews were instructed to attack the highest-value targets (battleships and aircraft carriers) or other high-value ships (cruisers and destroyers). Ground objectives were to be struck by the first wave of dive bombers. Fighters were commanded to strafe and destroy as many parked aircraft as possible, especially in the initial surge, to ensure they did not get into the air to intercept the bombers. The fighters were to refuel at the aircraft carriers when their fuel ran out and then return to action. Soldiers were to assist the CAP in any way they could, especially over American airfields.

Before the attack, the Imperial Japanese Navy dispatched reconnaissance floatplanes from the cruisers Chikuma and Tone, one over Oahu and the other over Lahaina Roads, Maui, with orders to report on the composition and whereabouts of the US fleet. Reconnaissance aircraft missions were unnecessary and risked alerting the US. Due to the reports of Japanese spy Takeo Yoshikawa, the makeup of the US fleet and readiness information in Pearl Harbor were already known. The Tone's floatplane and fleet submarine I-72 got a report that the US fleet was not present in the Lahaina harbour off Maui. Four more scout planes scoured the area between the Japanese carrier force (the Kid Butai) and Niihau to identify any counterattack.

Submarines

The Type A midget submarines were loaded onto the fleet submarines I-16, I-18, I-20, I-22, and I-24 for transfer to the waters off Oahu. On November 25, 1941, the five I-boats left Kure Naval District. They arrived within ten nautical miles (19 kilometres; 12 miles) of the mouth of Pearl Harbor on December 6 and deployed their miniature submarines at 01:00 Local Time on December 7. The minesweeper Condor sighted a midget submarine periscope southwest of the Pearl Harbor entry buoy at 03:42 Hawaiian time and reported the destroyer, Ward. On the other hand, Ward sank another midget submarine at 06:37 in the Pacific Theater's first American shots. Before being destroyed by Monaghan at 08:43, a midget submarine on the north adjacent of Ford Island missed the airplane tender Curtiss with her first torpedo and wasted the approaching destroyer, Monaghan, with her second. Ha-19, a third midget submarine, grounded twice, once outside the harbour entrance and again on the east coast of Oahu on December 8, when it was captured. Ensign Kazuo Sakamaki swam ashore and was arrested by Corporal David Akui of the Hawaii National Guard, becoming the first Japanese POW. A fourth was damaged by a depth charge strike and was abandoned by its crew before its torpedoes could be fired. In 1960, it was discovered on the outskirts of the harbour. At 00:41 on December 8, Japanese forces received a radio communication from a midget submarine alleging damage to one or more big warships inside Pearl Harbor.

Submersibles from the Hawaii Undersea Research Laboratory discovered the wreck of the fifth midget submarine in three pieces outside of Pearl Harbor in 1992, 2000, and 2001. The impact was found in a debris field where much surplus US military equipment, including vehicles and landing craft, was discarded after the war. Its torpedoes were both gone. Two torpedoes were fired at the light cruiser St. Louis at 10:04 near the Pearl Harbor entrance, while a potential torpedo was fired at destroyer Helm at 08:21.

Japanese Declaration of War

The raid happened before Japan issued a formal war order, but Admiral Yamamoto had no intention. He had initially planned for the strike to begin thirty minutes after Japan had informed the US that peace negotiations had ended. The attack, however, started before the notice could be conveyed. Tokyo sent the 5000-word notification (dubbed the "14-Part Message") to the Japanese Embassy in Washington in two blocks. The Japanese envoy took too long to transcribe the message to transmit it on time; in the end, it was not delivered until more than an hour after the attack began. (In fact, most of the message had already been decoded and translated by US codebreakers hours before he was supposed to deliver it.) The final section is often referred to as a declaration of war. While it was interpreted by several top US government and military officials as a strong indication that discussions were likely to be terminated and that war may erupt at any time, it did not declare war or cut diplomatic ties. The evening version of December 8 (late December 7 in the US) saw a announcement of war written on the front page of Japanese newspapers. Still, it was not delivered to the US government until the day after the attack. For decades, common opinion claimed that Japan struck without first cutting diplomatic relations due to mishaps and blunders that caused the transmission of a paper indicating war to Washington to be delayed. Takeo Iguchi, a law and international relations professor at Tokyo's International Christian University, discovered documents in 1999 that revealed a heated debate within the government over how, and indeed whether, to notify Washington of Japan's intention to end negotiations and start a war, including a December 7 entry in the war diary that stated, "Our deceptive diplomacy is steadily proceeding toward success." "The journal demonstrates that the army and navy did not wish to provide any legitimate declaration of war, or indeed even prior warning even of the termination of negotiations," Iguchi remarked of this.

First Wave Composition

Commander Mitsuo Fuchida led the initial attack wave of 183 planes launched north of Oahu. Due to technical difficulties, six planes were unable to take off. Three groups of planes were involved in the first attack:

1st Group (battleships and aircraft carriers as targets)

• Four sections of 49 Nakajima B5N Kate bombers armed with 800 kg (1760 lb) armour-piercing bombs (1 failed to launch)
• Four units of 40 B5N bombers equipped with Type 91 torpedoes

The Second Group (targets: Wheeler Field and Ford Island)

• 51 Aichi D3A Val dive bombers equipped with general-purpose bombs weighing 550 lb (249 kg) (3 failed to launch)
• (Aircraft at Ford Island, Wheeler Field, Hickam Field, Barber's Point, and Kaneohe) 3rd Group
• 43 Mitsubishi A6M "Zero" fighters provide air control and strafing. (2 attempts to launch failed)

The first wave was detected by the US Army SCR-270 radar at Opana Point on the island's northern point as it reached Oahu. This post had been in training for months but was not in service. Privates George Elliot Jr. and Joseph Lockard, the operators, informed Private Joseph P. McDonald, a private stationed at Fort Shafter's Intercept Center at Pearl Harbor, of a target. However, Lieutenant Kermit A. Tyler, a freshly posted officer at the Intercept Center's thinly staffed Intercept Center, assumed it was the arrival of six B-17 bombers from California. While the operatives had never seen a formation as large on radar, they failed to inform Tyler of its size. The Japanese planes were approaching very close (only a few degrees difference) to the bombers. While the operatives had never seen a formation as large on radar, they failed to inform Tyler of its size. Moreover, Tyler could not disclose the operators about the six B-17s scheduled to arrive owing to security concerns (even though it was widely known).

As the initial wave of planes reached Oahu, they came across and shot down several American planes. At least one of them sent out a jumbled warning over the radio. When the Japanese air attack began at 7:48 a.m., other notices from ships off the harbour entry were still being processed or awaiting confirmation. With the attack on Kaneohe, it was 3:18 a.m. Hawaiian Time (3:18 a.m. Japanese Standard Time, as kept by ships of the Kido Butai). In two waves, a total of 353 Japanese planes arrived on Oahu. The first wave was led by slow, vulnerable torpedo bombers, who took advantage of the first moments of astonishment to attack the most important ships present (the battleships), while dive bombers attacked US air bases across Oahu, starting with the largest, Hickam Field, and Wheeler Field, the leading US Army Air Forces fighter base. The second wave of 171 planes targeted the Army Air Forces' Bellows Field near Kaneohe on the island's windward side and Ford Island. A few P-36 Hawks, P-40 Warhawks, and SBD Dauntless dive bombers from the carrier Enterprise provided the only aircraft opposition.

About eight of the forty-nine 800 kg armour-piercing bombs delivered in the first wave attack struck their targeted battleship targets. Two bombs exploded on impact, one detonated before piercing an unarmored deck, and the third was a dud. Thirteen of the forty torpedoes were aimed at battleships, while four were aimed at other ships. Alarms, bombs exploding, and gunfire roused personnel onboard US ships, leading bleary-eyed men to dress and rush to General Quarters stations. (The well-known message, "Pearl Harbor was bombed by planes. This isn't a practice session ", was conveyed by Patrol Wing Two's headquarters, the first senior Hawaiian command to respond.) The defenders were caught off guard. Ammunition lockers were secured, aircraft were parked wingtip to wingtip in the open to prevent sabotage, and guns were left unattended (none of the Navy's 5). "Only four of the 31 Army batteries saw combat, and only a fifth of the /38s was used).

Nevertheless, many American military personnel responded to the attack effectively despite the low alert level. The ship's antiaircraft weapons were commanded by Ensign Joseph Taussig Jr., who was seriously injured but remained on duty. In the absence of the skipper, Lt. Commander F. J. Thomas took command of Nevada and got her going until 9:10 a.m. One of the destroyers, the Aylwin, set out with only four officers on board, all ensigns with no more than a year's experience at sea; she remained at sea for 36 hours until her commanding officer returned. West Virginia's commanding officer, Captain Mervyn Bennion, led his men until he was killed by fragments from a bomb that hit Tennessee, anchored nearby.

Second Wave Composition

Lieutenant-Commander Shigekazu Shimazaki led the second wave of 171 planes, including 54 B5Ns, 81 D3As, and 36 A6Ms. Due to mechanical difficulties, four airliners were unable to take off. Therefore, there were three groups of planes in this wave and its targets:

1st Group — 54 B5Ns armed with general-purpose bombs weighing 550 lb (249 kg) and 132 lb (60 kg).

• On Kaneohe, Ford Island, and Barbers Point, there are 27 B5Ns with aircraft and hangars.
• Hickam Field has 27 B5Ns with hangars and aircraft.

Second Group (targets: aircraft carriers and cruisers)

• Four sections of 78 D3As loaded with 550 lb (249 kilograms) general-purpose bombs (3 aborted)
• Wheeler Field, Aircraft at Ford Island, Hickam Field, Barber's Point, and Kaneohe

3rd Group

• 35 A6Ms for strafing and defence (1 aborted)

Three groups were formed for the second wave. One was sent to assault Kneohe, while the others were assigned to attack Pearl Harbor. The various portions arrived at the attack point practically simultaneously from multiple directions.

American Casualties and Damage

The attack ended ninety minutes after it began. Two hundred eighteen militaries and airmen who were portion of the Military before the independent United States Air Force in 1947 were murdered, and 364 others were injured; 109 Marines were killed, and 69 were injured, and 68 civilians were murdered, and 35 were wounded. There were 2,403 Americans killed and 1,143 wounded in total. Five battleships were among the eighteen ships lost or stranded. Because there was no state of war at the time of the attack, all of the Americans killed or wounded were lawfully non-combatants. Later it was hit by a modified 16-inch (410 mm) shell, the explosion of Arizona's forward magazine killed nearly half of the Americans.

According to author Craig Nelson, the great majority of the US sailors killed at Pearl Harbor were junior enlisted soldiers. "The Navy commanders all lived in residences, and the junior people were on the boats," Nelson explained, "so very much all of the people who died in the direct line of the attack were very subordinate people." "So everyone whose tale is told there is around 17 or 18 years old."

Nine Honolulu Fire Department (HFD) firefighters were among the notable civilian victims, becoming the only fire department employees on American territory to be attacked by a foreign power in history as they responded to Hickam Field during the bombing of Honolulu. Engine 6 fireman Harry Tuck Lee Pang was killed by machine-gun fire from a Japanese plane near the hangars. Captains Thomas Macy and John Carreira of Engines 4 and 1 died fighting fires inside the hangar when a Japanese bomb exploded through the roof. Six more firefighters were injured by shrapnel from the Japanese. For their peacetime activities that day on June 13, 1944, the wounded received Purple Hearts (reserved initially for service members injured by enemy action while participating in armed conflicts); the three firefighters killed did not receive theirs until December 7, 1984, on the 43rd anniversary of the attack. The nine men were the first non-military firefighters to win such an honour in US history.

Nevada attempted to leave the harbour after being hit by a torpedo and catching fire amidships. As she set sail, she was attacked by a swarm of Japanese bombers, and she took additional hits from 250 lb (113 kg) bombs, sparking more fires. She was beached on purpose to avoid blocking the harbour entrance. Two bombs and two torpedoes were dropped on California. The crew might have kept her afloat if they hadn't been ordered to abandon ship just as the pumps were being powered up. Burning oil from Arizona and West Virginia floated down on her, making the scene appear even worse. Torpedoes sunk the disarmed target ship Utah twice. West Virginia was hit by seven torpedoes, which ripped the rudder from her boat. Oklahoma was hit by four torpedoes, which landed above her belt armour, causing her to capsize. Two of the modified 16s hit Maryland. "Both shells exploded, although none did significant damage.

Despite focusing on battleships (the most significant boat present), the Japanese did not disregard other targets. The light vessel Helena was torpedoed, and the blast caused the nearby minelayer Oglala to capsize. Cassin and Downes, two dry-dock destroyers, were destroyed when bombs penetrated their fuel bunkers. The leaking fuel caught fire and attempts to extinguish the fire by flooding the dry dock caused the burning oil to ascend, causing both to burn out. Cassin rolled against Downes after slipping from her keel blocks. A torpedo sank the Raleigh, a light cruiser. Despite being damaged, the light cruiser Honolulu stayed on duty. Vestal's repair vessel, which was moored alongside Arizona, was severely damaged and washed up on the beach. Curtiss, a seaplane tender, was also damaged. Two bombs penetrated the destroyer Shaw's forward magazine, causing severe damage. 188 American aircraft were demolished, and 159 were wounded in Hawaii, with 155 remaining on the ground.

Almost no one was truly prepared to leave the base to defend it. Six Army Air Forces pilots were accredited with put down at least one Japanese aircraft throughout the attack. Eight Army Air Forces pilots succeeded to get airborne during the attack, and six were credited with Thirty PBYs were destroyed in Hawaii, with three PBYs on patrol at the time of the attack returning unharmed. On top of that, the friendly fire took down a few US planes, including four on an inbound flight from Enterprise. Nine civilian aircraft were flying in the neighbourhood of Pearl Harbor at the time of the attack. Three of them were shot down.

Japanese Losses

The raid killed 55 Japanese airmen and nine submariners, and one, Kazuo Sakamaki, was captured. In addition, 350 of Japan's 414 available planes participated in the raid, with 29 aircraft lost.

Possible Third Wave

Several subordinate Japanese officers, particularly Fuchida and Genda, encouraged Nagumo to launch a third strike to destroy as much of Pearl Harbor's fuel and torpedo storage, maintenance, and dry dock facilities as feasible. Genda, who had unsuccessfully campaigned for invading Hawaii following the air attack, considered that three strikes were required to cripple the facility as much as possible without an invasion. In addition, the captains of the task force's other five carriers reported that they were willing and ready to launch a third strike.

According to military historians, the loss of these shore facilities would have hampered the US Pacific Fleet far more than the loss of battleships. If they had been eliminated, "major (American) operations in the Pacific would have been postponed for more than a year"; "it would have delayed the war another two years," according to Admiral Chester W. Nimitz, subsequently Commander in Chief of the Pacific Fleet. On the other hand, Nagumo opted to retire for various reasons: During the second strike, American antiaircraft effectiveness had greatly improved, and the second wave accounted for two-thirds of Japan's losses.

Nagumo believed that launching a third strike would mean sacrificing three-quarters of the Combined Fleet's strength to eliminate the remaining targets (which included the installations) while incurring heavier aircraft losses.

The whereabouts of the American carriers remained a mystery. In addition, the admiral was concerned that his force had moved into a range of American bombers on the ground. Finally, Nagumo was unsure whether the United States had enough surviving planes in Hawaii to attack his carriers.

A third wave would have necessitated extensive planning and turnaround time, as well as the requirement that was returning planes land at night. Only the Royal Navy had perfected night carrier techniques at the time; therefore, this was a significant danger. Because he was approaching the end of his logistical assistance, the task force's fuel situation did not allow him to stay in the waters north of Pearl Harbor for much longer. To do so would risk running out of fuel and possibly having to abandon destroyers en route home. He didn't want to risk any more losses because he thought the second hit had virtually accomplished his mission's primary goal—the neutralization of the US Pacific Fleet. Furthermore, the IJN had a policy of prioritizing the preservation of strength over the utter destruction of the opponent.

Yamamoto backed Nagumo's withdrawal without firing the third wave at a conference aboard his flagship the following day. In retrospect, saving the important dockyards, maintenance shops, and the oil tank farm allowed the US to respond to Japanese actions in the Pacific rather rapidly. Nevertheless, Yamamoto later expressed sorrow over Nagumo's choice to withdraw and declared that failing to command the third strike was a grave error.

Afterward a methodical search for survivors, Captain Homer N. Wallin led a formal salvage operation. Divers from the Navy, the Pearl Harbor Naval Shipyard, and civilian servicers began work on the ships that could be refloated in the area surrounding Pearl Harbor. They repaired holes, removed debris, and drained water from boats. Divers from the Navy worked inside the stricken ships. Five battleships and two cruisers were repaired or refloated within six months, taking them to shipyards in Pearl Harbor and the mainland for comprehensive repairs. Intensive recovery activities lasted another year, resulting in 20,000 person-hours spent underwater.

Arizona and the target vessel Utah were too severely damaged to be salvaged. Therefore they were sunk, with Arizona serving as a battle memorial. While Oklahoma was successfully raised, it was never repaired and capsized in 1947 while being towed to the mainland. Nevada was challenging to expand and improve, and two crew members died after inhaling poisonous gases accumulated inside the ship. When possible, armament and equipment were removed from damaged ships and repurposed for other vessels.

Around 2:22 p.m. Eastern Time (8:52 a.m. Hawaiian Time), White House Press Secretary Stephen Early made the following announcement: "The Japanese have attacked Pearl Harbor from the air, as well as all naval and military activities on the island of Oahu, the principal American base in the Hawaiian islands." Early made several other statements to around 150 White House reporters as information became available throughout the afternoon. At nearly 2:25 p.m. Eastern Time, initial word of the attack began to circulate on news wires. Around 2:30 p.m. Eastern Time, the CBS radio network's scheduled news program, World News Today, broadcast the first radio coverage (which, at the time, was the earliest option for regular people to learn about the attack). The original report was read by John Charles Daly, who then turned to London, where Robert Trout improvised on the anticipated London reply. Around 2:33 p.m. Eastern Time, the initial report on NBC cut into a play, a dramatization of The Inspector-General, and lasted only 21 seconds. Unlike the later norm with significant news developments, there were only brief interruptions of scheduled commercial programming. A contemporary newspaper report compared the attack to the Battle of Port Arthur 37 years earlier, when the Imperial Japanese Navy attacked the Imperial Russian Navy, sparking the Russo-Japanese War. Modern writers have continued to draw comparisons between the attacks, albeit with greater objectivity.

Roosevelt delivered his famed Day of Infamy Speech to a Joint Session of Congress the day after the attack, calling for a formal declaration of war on the Japanese Empire. Less than an hour later, Congress granted his request. However, even though the Tripartite Pact did not require it, Germany and Italy declared war on the United States on December 11. Later that day, Congress issued a declaration of war against Germany and Italy. The UK had been at war with Germany since September 1939 and Italy since June 1940, and British Prime Minister Winston Churchill had threatened to declare war on the United States "within the hour" of a Japanese attack.

When Churchill learned of the Japanese attacks on Malaya, Singapore, and Hong Kong, he decided there was no need to wait or consult the US administration any longer and immediately called the Japanese ambassador. As a result, the United Kingdom declared war on Japan nine hours ahead of the United States.

The Allies in the Pacific Theater was taken aback by the strike at first. More losses exacerbated the frightening setback. A few hours later, Japan launched an attack on the Philippines (because of the time difference, it was December 8 in the Philippines). The battlewagons Prince of Wales and Repulse were sunk off the coast of Malaya only three days after the attack on Pearl Harbor, prompting Churchill to reflect later, "I never received a more direct shock during the war. The full horror of the news hit me as I turned and twisted in bed. Except for the American survivors of Pearl Harbor who were rushing back to California, there were no American or British capital ships in the Indian Ocean or Pacific. Japan reigned supreme over this vast expanse of water while we were all weak and naked." Pearl Harbor was widely referenced in American propaganda throughout the war.

Another result of the invasion on Pearl Harbor and its aftermath (particularly the Niihau incident) was the relocation of Japanese-American residents and citizens to nearby internment camps. Hundreds of Japanese-American leaders were apprehended and taken to high-security camps like Sand Island at the mouth of Honolulu harbour and Kilauea Military Camp on the island of Hawaii within hours of the attack. More than 110,000 Japanese Americans, virtually all of whom lived on the West Coast, were eventually detained, but only 1,200 to 1,800 were interned in Hawaii. However, Japanese Americans made up more than one-third of the population.

The attack had international ramifications as well. The Pacific Ocean-bordering Canadian province of British Columbia has long had a considerable population of Japanese immigrants and their Japanese-Canadian descendants. The Pearl Harbor attack exacerbated pre-war tensions, prompting a response from the Canadian government. Under the War Measures Act, Order-in-Council P.C. no. 1486 was issued on February 24, 1942, allowing for the compulsory deportation of all Canadians of Japanese heritage from British Columbia and preventing their return. On March 4, the Act's requirements for the evacuation of Japanese-Canadians were passed. As a result, 12,000 people were transported to interior camps, 2,000 to road camps, and 2,000 were forced to labour on sugar beet farms in the plains. The American servicemen who illustrious themselves in combat at Pearl Harbor were awarded 15 Medals of Honor, 53 Silver Stars, 51 Navy Crosses, four Navy and Marine Corps Medals, one Illustrious Flying Cross, four Illustrious Service Crosses, one Illustrious Service Medal, and three Bronze Star Medals in the aftermath of the attack. In addition, the Pearl Harbor Commemorative Medal, a special military honour, was eventually granted for all military veterans of the attack.

Niihau Incident

The Japanese planners of the Pearl Harbor attack determined that some means of rescuing fliers whose planes were too heavily damaged to return to the carriers were required. The island of Niihau was chosen as the rescue point since it was only 30 minutes flight time from Pearl Harbor. In the attack on Wheeler, Petty Officer Shigenori Nishikaichi of Hiryu's Zero was damaged, so he flew to the rescue site. Unfortunately, the plane was significantly damaged when it landed. One local Hawaiians rescued Nishikaichi from the wreckage and seized the pilot's weapon, maps, codes, and other documents, knowing that the United States and Japan were at odds. The island occupants did not have access to telephones or radios. Thus they were utterly unaware of the attack on Pearl Harbor. In an attempt to acquire the documents, Nishikaichi enlisted the help of three Japanese-American people. Nishikaichi was murdered, and a Hawaiian civilian was injured in the ensuing battles; one collaborator committed suicide, while his wife and the third collaborator were imprisoned. The apparent ease with which local ethnic Japanese residents sought Nishikaichi's assistance alarmed many and tended to bolster those who claimed that local Japanese could not be trusted.

Strategic Implications

"We scored a great tactical victory at Pearl Harbor and thereby lost the war," said Admiral Hara Tadaichi, summarizing the Japanese win. While the attack successfully achieved its goal, it was primarily needless. The US Navy had opted to stop 'charging' across the Pacific towards the Philippines in response to an outbreak of war in 1935, unbeknownst to Yamamoto, who devised the initial plan (in keeping with the evolution of Plan Orange). Instead, in 1940, the US developed "Plan Dog," which focused on keeping the IJN out of the eastern Pacific and away from Australia's transport lines while the US focused on conquering Nazi Germany.

Fortunately, the American aircraft carriers were spared; otherwise, the Pacific Fleet's ability to execute aggressive operations would have been halt for a year or more. As it happened, the loss of the battleships forced the US Navy to rely on its aircraft carriers and submarines—the very weapons that the US Navy used to halt and finally reverse the Japanese advance. Even though six of the eight battleships were repaired and returned to service, their poor speed and high fuel consumption limited their deployment. They were principally used for shore bombardment (their only significant action being the Battle of Surigao Strait in October 1944). According to Captain Alfred Thayer Mahan's doctrine, the ultimate Pacific conflict would be fought by battleships, a critical mistake in Japanese strategic thinking. As a result, Yamamoto (and his successors) stocked up on battleships in preparation for a "decisive battle" that never materialized. Since the Japanese were so confident in their ability to win quickly, they ignored Pearl Harbor's navy overhaul yards, oil tank farms, submarine base, and ancient headquarters building.

These targets were left off of Genda's index, despite being more crucial to the American war effort in the Pacific than any battleship. The repair shops and fuel depots survived, allowing Pearl Harbor to continue providing logistical support to US Navy operations such as the Doolittle Raid and the Coral Sea and Midway Battles. Submarines crippled the importation of oil and raw materials, immobilizing the Imperial Japanese Navy's heavy ships and bringing Japan's economy to a halt. By the end of 1942, the number of raw materials obtained had been cut in half, to a calamitous ten million tons, while oil was nearly stopped. Finally, the cryptanalytic unit, which played a vital role in the Midway ambush and the success of the Submarine Force, was housed in the basement of the Old Administration Building.

Retrospective Debate on American Intelligence

Since the Japanese attack, there has been disagreement about how and why the US was taken off guard and how American officials were aware of Japanese plans and other associated subjects. Mason Patrick, Chief of the US Air Forces, was worried about military vulnerabilities in the Pacific as early as 1924 when he sent General Billy Mitchell on a survey of the Pacific and the East. Mitchell's second study, which identified vulnerabilities in Hawaii, was described by Patrick as a "theoretical treatise on airpower usage in the Pacific, which, in all probability, will be of exceptional value some 10 or 15 years hence."

Pearl was exposed to such an attack in at least two naval war games, one in 1932 and another in 1936. Admiral James Richardson was relieved of command after publicly criticizing President Franklin D. Roosevelt's decision to relocate the Pacific fleet to Pearl Harbor. Conspiracy theories have sprung out due to military and political leaders' decisions to reject these warnings.