Here’s another ‘what if’ version of history: what if the Japanese had immediately invaded
Hawaii after attacking Pearl Harbor? How
would the war have progressed from that point?
Let’s see.
Note: Credit for this idea goes to blog reader
‘Purple Calico’ who suggested the topic during the recent open post discussion.
(3)
The initial premise is that the attack on Pearl Harbor and
all the related events happened exactly as history records except that the
Japanese fleet contained an invasion force and the Japanese continued on to
Pearl Harbor rather than turning away.
To review, the Japanese strike fleet consisted of 6 aircraft
carriers (Akagi, Kaga, Sōryū, Hiryū, Shōkaku, and Zuikaku) with well over
400 aircraft, protected by 2 battleships, 3 cruisers, and 9 destroyers (all
actual). Accompanying the strike were 8
tankers (actual) which would prove crucial in our alter-history by sustaining
the fleets while the island was being secured.
In addition, 23 fleet submarines (actual, 4) were assigned to
provide containment around Pearl Harbor to prevent any surviving US ships from
escaping to open waters (1) and screening for the strike and invasion fleets. A third were assigned to screen the fleet to
the east of Oahu, another third capped the Pearl Harbor channel to the south,
and the remaining third patrolled the waters to the west of Oahu.
The alter-historical addition to the Japanese strike fleet
is an invasion force consisted of an armored division with 10,000 men and 270
tanks plus dozens of artillery and anti-tank guns plus an infantry division of
almost 25,000 men supported by several dozen artillery guns, all loaded on
dozens of transport vessels.
The attack on Pearl Harbor came from the north with the 1st
wave launching around 220 miles north of Pearl Harbor. The strike fleet continued to sail east and
launched the 2nd wave from the northeast.
The first two attack waves succeeded in sinking or damaging
nearly all the battleships and cruisers and eliminated effective aerial
resistance. Of the 402 American aircraft
in Hawaii, 188 were destroyed and 159 damaged, 155 of them on the ground
(actual).
Note: An outstanding map of Pearl Harbor ships and
facilities at the moment of attack can be found on the National Geographic
website. (2)
What follows is a descriptive alter-historical summary of
events beginning immediately after the 2nd assault wave of Japanese
aircraft.
A 3rd wave was launched from east of Oahu and
focused on the ten or so destroyers which had been largely untouched in the
first two strikes and any remaining aircraft on the ground. By the time the 3rd wave was
finished, there were very few undamaged ships in Pearl Harbor.
The strike fleet continued sailing in a clockwise circle around
Oahu, escorting the transport vessels.
The land assault would be focused on the militarized island of Oahu
which contained the Pearl Harbor naval base, Marine barracks, and multiple air
fields. The remaining Hawaiian islands
did not need to be occupied. This
allowed the Japanese to concentrate their resources on a single small island
only 20 miles or so across.
With no American air power to worry about, the two Japanese
battleships raced ahead of the rest of the invasion and strike fleets and
entered the Pearl Harbor channel at dusk.
Their mission was to destroy any remaining ships, bombard the facilities
that the Japanese didn’t need to occupy and reuse, and to distract from the
assault force that began their landings at the same time. There was risk with attempting an evening
landing rather than waiting for dawn but it was felt that the risk was worth it
to maintain the shock and confusion that the reeling Americans were under.
As it turned out, the Japanese battleships were hugely
successful with the Americans firing on their own ships as much as the Japanese
did due to the darkness, confusion, and panic.
With reports of Japanese troop landings, and the evidence of Japanese
ships in the harbor, American troops began firing on their own ground forces as
they were totally untrained and unprepared for night combat and had not trained
for friendly forces identification. By
morning, the Japanese ground forces were well established and by the end of the
day on the 8th were in control of the Pearl Harbor facilities.
 |
| Japanese Forces Landing on Oahu |
The USS Enterprise, returning from delivering Wildcats to
Wake Island, was 215 miles west of Pearl Harbor when the Japanese attacks
began. Several of Enterprise’s SBDs had
flown ahead to Pearl and were shot down by friendly fire. Enterprise spent the day of the 7th
searching for the Japanese strike fleet but found nothing since the Japanese
fleets were on the opposite side of Oahu.
As reports of Japanese invasion forces reached Enterprise, Admiral
Halsey headed southeast and began to assemble an aerial strike force. Unfortunately, that brought Enterprise into
the teeth of the Japanese submarine screen and a Japanese submarine found her
and put three torpedoes into the ship.
Over the next several hours, a second Japanese submarine was able to
approach and hit Enterprise with two more torpedoes. Her fate was sealed. Enterprise was a blazing wreck and eventually
sank during the night of the 8th.
 |
| Enterprise Torpedoed and Sinking |
Meanwhile, Lexington, which had been on a mission to deliver
planes to Midway, found herself caught halfway between Midway and Pearl Harbor
and with her escorts low on fuel due to previous refueling difficulties
(actual). With Enterprise sunk, the
Japanese dispatched four carriers to search for Lexington and, on the 12th,
found her, thus setting the stage for the first carrier battle where the
opposing ships never saw each other.
Both sides launched nearly simultaneous attacks. Lexington, with only a single air group which
included over a dozen older Brewster Buffalos, was unable to fight off the
Japanese attack and suffered two bomb hits, two torpedoes, and a damaged
Japanese plane that dove into the carrier.
Lexington’s strike, facing the defensive CAP of four carriers, managed to
score two bomb hits on the Kaga which damaged the carrier enough to curtail
flight operations but did not sink it.
Both sides recovered their strikes but the Japanese, with greater
numbers, were able to launch a second, standby, strike before Lexington could
effect repairs sufficient to assemble another strike. The second strike finished off the Lexington.
This left Saratoga, which was training her air group in San
Diego, as the only US carrier in the Pacific.
Yorktown, Hornet, and Ranger and Wasp were training in Norfolk. Ranger was considered unsuited for the
Pacific and was destined for Atlantic and European operations. It would be many weeks before Yorktown,
Hornet, and Wasp could be moved to the Pacific and the Japanese used that time
to secure Pearl Harbor and set it up as their forward base. Japanese army aircraft fighters were ferried
to the island along with long range patrol planes and bombers.
One of the major benefits for the Japanese in seizing Pearl
Harbor was the presence of the drydocks which they had wisely and carefully
avoided damaging in the initial attacks and which were captured largely intact
and quickly returned to service. Damaged
Japanese ships which might otherwise have had to return to Japan for repair,
were able to be serviced locally, at Pearl Harbor, and returned to combat much
quicker. This was significant as even
the base at Truk lacked significant repair facilities.
Fall of Wake – On 11-Dec-1941, Wake defenders fought off the
first Japanese landing attempt, sinking two Japanese destroyers with coastal
defense guns and Wildcat aircraft. A
second assault initiated shortly after midnight on 23-Dec-1941 succeeded and
the island fell later that same day.
Seizure of Tulagi and Port Moresby (Coral Sea) – The
Japanese planned to seize Tulagi and Port Moresby in operations that began in
April 1942. The Americans were able to
intercept and decipher Japanese signals and knew the general location and
timing of the operations. Having lost
Pearl Harbor, the threat to Australia as a forward base was considered strategically
vital and an operation to intercept the Japanese in or around the Coral Sea was
initiated. The carrier Yorktown,
recently arrived in the Pacific, was patrolling in the area to the west of
Australia and Saratoga was dispatched from San Diego to join her and meet the
Japanese invasion fleet. The Japanese
sent the Carriers Shokaku, Zuikaku, and Shoho to screen the invasion forces
from the north and a surface force centered around the battleship Yamato
approached from the northeast from Pearl Harbor. Despite the efforts of their respective scout
aircraft, the two sides stumbled across each other during the night of 6-May
with the Yamato group sighting the Yorktown and Saratoga which had joined up
the previous day. The Japanese and
American destroyer screens made contact and exchanged fire in a wild night
battle which the Japanese cruisers and the Yamato quickly jumped into. When word came that a Japanese battleship was
part of the attack, the American carriers conducted an impromptu and untrained-for
night launch and attack. Despite the
darkness and their lack of training, the untrained flyers succeeded in hitting
Yamato with one torpedo and a cruiser was hit with two bombs. Unfortunately, in the darkness, confusion,
and co-mingling of the ships, the flyers also torpedoed and sank a US
destroyer. As dawn approached, and
fearing further aerial attacks, the Japanese broke off the attack and steamed
away.
 |
| Yorktown and Saratoga Night Attack on Yamato |
However, with the US carrier force now located, the Japanese
carriers launched a heavy dawn attack which caught the US carriers and their
exhausted pilots unprepared. Saratoga
was heavily damaged by multiple torpedoes and bombs and Yorktown suffered two
bomb hits. When the attack ended,
Yorktown, whose dawn scouting planes had located the Japanese carriers, was
still able to conduct flight operations and launched a counterattack which
caught the Japanese carriers refueling and rearming their aircraft. Shoho was sunk and Shokaku was heavily
damaged.
After recovering her aircraft, Yorktown broke off the
engagement and retired to the southeast and back to San Diego for repairs. Saratoga was taken under tow but the Yamato
group, reversing course and returning to the area to mop up, fell upon the
carrier and sank it with gunfire.
The Battle of the Coral Sea, as it came to be known, was a
tactical draw but because the US was unable to stop the Japanese invasion fleet
which still had sizable carrier and surface forces in the area to provide
protection, the Japanese were able to complete the seizure of Port Moresby
which was then used as a staging area to threaten Australia directly.
With the loss of Saratoga, only the Hornet, Wasp, and
damaged Yorktown remained from the pre-war US carrier force.
The Japanese then seized Midway, costing the US the valuable
PBY Catalina patrol and scouting base.
Despite having knowledge of the Japanese intentions via signals
analysis, the US simply didn’t have the naval strength to contest the Japanese
invasion.
The US was now forced to operate from Australia, the Aleutians,
and San Diego. None of these options was
desirable although Australia was, at least, near the action due to the Japanese
seizures. US efforts for the next
several months centered on reinforcing Australia and beefing up its
defenses. If Australia fell, the US
would be effectively ejected from the Pacific theatre.
Taking a cue from the Germans, the Japanese began conducting
aggressive Australian convoy interdiction using submarines based out of Pearl
Harbor. The Battle of the Pacific,
mirroring the Battle of the Atlantic, became a logistic supply contest with the
US attempting to reinforce Australia and the Japanese attempting to cut the
supply line.
The Japanese, having essentially secured the Pacific now
focused on a holding strategy in an attempt to force the US into a negotiated
peace. The Japanese believed that the
US, already occupied with the war in Europe, would grow weary of fighting a
difficult war in the Pacific and lacked the stomach for the casualties such an
endeavor would entail.
To that end, in late 1942 the Japanese dispatched a strike
force of carriers and battleships to the west coast of the US to conduct
bombardment raids which, it was hoped, would further discourage a demoralized
populace and force the US to negotiate. The
strike force arrived off the coast of Washington and began moving south,
bombarding cities and targets of opportunity as they went. The intent was to inflict some casualties and
instill fear in the populace rather than achieve any specific military success. After 24 hours of nearly continuous
bombardment, the group turned away and retired to avoid the inevitable surge of
US naval forces to the area from San Francisco and San Diego.
 |
| Japanese Battleship Bombarding Washington Coast |
While the operation was executed flawlessly the reaction of
the American people was a surge of anger, defiance, and cries for revenge and
retaliation. As a result of the raid, US
determination to defeat Japan was greater than ever, much to the disbelief of
the Japanese strategists.
There was little doubt that the US needed to recapture Pearl
Harbor to support the war with Japan.
However, by this time, Japan had had a year to fortify the base and
seizing it by a direct assault with the closest support being the US west coast
was not immediately feasible. Instead,
US military strategists opted to seize Midway atoll first and then use Midway
to screen and support a subsequent assault against Pearl Harbor. An invasion force consisting of Maj. Gen.
Vandegrift’s 1st Marine Division and supported by the carriers Yorktown,
Hornet, Wasp, and the newly arrived Essex along with RAdm. Willis ‘Ching’ Lee’s
battleship group of North Carolina, Washington, Indiana, and South Dakota was
assembled in the Aleutians at Dutch Harbor and sailed for Midway in May
1943.
As the force approached Midway from the north, the carriers
broke off and circled to the east to take a position to the southeast of
Midway, somewhat between it and Pearl Harbor.
As expected, the battleships and troop transports were spotted by long
range patrol planes from Midway. The
Japanese surged four carriers and their escorts, including the battleships
Yamato, the newly arrived Musashi, and the older battleships Nagato, Mutsu, and
Fuso from Pearl Harbor to intercept the American force.
The US transport fleet hung back while the battleship group
and its escorts took the lead. As the US
fleet approached Midway, the Japanese launched two aerial strikes of high level
bombers from Midway. The concentrated
anti-aircraft fire of the US battleships and escorts, combined with the
inherent inaccuracy of high level bombing resulted in only two hits: one bomb hit the South Dakota resulting in
only minor damage and a more serious hit on a cruiser which was forced to
retire northward.
Having yet to spot any US carriers, the Japanese saw the
chance to engage the US battleships in the long-desired battle line
confrontation. The Japanese battleships
sprinted ahead to meet the US battleships.
 |
| Japanese Battle Line Steaming To Meet US Battleships |
Shortly after, scout planes from the Japanese and US carrier
forces located each other, roughly simultaneously and both sides launched
strikes at the other’s carriers. Each
realized that the carriers were the priority targets and that their respective
battleship forces would have to take care of themselves without the benefit of
air cover.
The Japanese strike aircraft reached the American carriers
first and managed to penetrate the carriers CAP and escort screen to put two
torpedoes into Hornet and one into Wasp.
Essex and Wasp were each hit by two bombs. The US strike failed to achieve any torpedo
hits but put three bombs into Akagi, and two into Soryu. At the end of the exchange, Wasp was left
ablaze and drifting while Essex worked frantically to control internal fires and
patch her flight deck. Hornet was slowed
due to flooding but otherwise operational.
On the Japanese side, Japanese damage control measures proved to be less
effective than US efforts and Akagi was left a wreck and Soryu was badly
damaged but working to regain operational ability.
A brief pause ensued while both sides worked on damage
control and refueled and rearmed for a follow up strike.
Meanwhile, to the northwest, the US battleships, using their
SOC Seagull and OS2U Kingfisher scout planes, were aware of the approaching
Japanese battleship group and moved to meet them.
While the two forces sailed towards each other, the carriers
launched their second strikes. This
time, the US carriers were able to turn their strike groups around a bit faster
than the Japanese and struck first. The
pilots bypassed the blazing Akagi and concentrated on Kaga and Hiryu, managing
to put a single torpedo into Kaga along with three bombs. Hiryu suffered one bomb hit and two near
misses. The Japanese strike found Hornet
and Essex and put three torpedoes into Hornet along with two bombs and Essex
was hit by another bomb and a torpedo.
Both strikes returned to their carriers and both carrier groups broke
off from the engagement, too damaged to continue.
By this time, the approaching battleship groups were
entering into range of each other. This
turned into the classic battle line engagement with the two groups turning to
face each other. Thanks to the Yamato
and Musashi the Japanese battleships held an initial range advantage and opened
fire at around 44,000 yds. The American
battleships, being outranged, continued to close thus presenting the Japanese
with the opportunity to ‘cross the T’ at long range. South Dakota, in the lead and seemingly a
hard luck ship, was straddled several times and suffered one direct hit from an
18” shell which knocked out one of the forward turrets.
As the US ships reached 35,000 yds, they turned onto a nearly
parallel course, closing slowly. At this
point, all the battleships were engaged, each picking their targets at
will. The older Japanese battleships
proved to be susceptible to the US 16” shells and suffered several direct hits
causing extensive damage and slowly reducing their firepower as mounts were hit
and disabled. Yamato and Musashi proved
quite resilient and several hits from 16” shells destroyed secondary guns and
started fires but were unable to silence their main batteries. The US battleships were hit multiple times,
except for Washington, and were slowly being pounded down.
At this point, the three older Japanese battleships fell
behind and out of the battle as did the South Dakota. That left the Yamato and Musashi engaged with
Washington, North Carolina, and Indiana.
The US had a greater combined rate of fire while the Japanese had
heavier firepower. As the battle dragged
on, all the ships suffered additional hits and were slowly being worn down but
the greater volume of fire from the American ships began to tell. The Japanese broke off the engagement and the
battered Americans were quite willing to let them go.
Mutso and Fuso eventually sank, as did the South
Dakota. The remaining ships on both
sides would be out of the war for several months.
 |
| South Dakota Fighting Mutso and Fuso |
In the aftermath, the battle was a tactical draw with the
Japanese losing two carriers, Akagi and Kaga, plus two older battleships and
the US also losing two carriers, Hornet and Wasp, plus the South Dakota. However, strategically, the Japanese failed
to stop the American invasion force and Midway was seized thus setting the
stage for the eventual recapture of Pearl Harbor. Historians view the Battle of Midway as the
turning point of the war.
After Midway, the US war industry began to hit its stride
and new Essex class carriers began arriving along with the new Iowa class
battleships and replacement aircraft and pilots. Japan was unable to match the industrial
output and could not replace their losses as readily. This trend would continue and worsen as the
war progressed. The end was inevitable
although four more years of bitter fighting still lay ahead.
__________________________________
(1)Naval History and Heritage Command website,
“An Advance
Expeditionary Force of large submarines, five of them carrying midget
submarines, was sent to scout around Hawaii, dispatch the midgets into Pearl
Harbor to attack ships there, and torpedo American warships that might escape
to sea.”
https://www.history.navy.mil/our-collections/photography/wars-and-events/world-war-ii/pearl-harbor-raid/japanese-forces-in-the-pearl-harbor-attack.html
