The scenario is that the Japanese fleet was destroyed on 6th December (i.e. the day before the attack on Pearl Harbor). We might know that it would be a somewhat justified move, but if the US actually did that it would just appear very aggressive and the Japanese could claim innocence.
Even with the justification of Japan preparing to attack other territories (they hadn’t done it yet) it would look very bad without a declaration of war at a minimum.
We would have had, in hours if not days, confirmation of Japanese intentions from the Japanese diplomatic cables themselves.
Second, Americans are not, in fact, incredible morons, and a huge Japanese fleet armed and ready to launch an massive first-strike attack bearin g down on the Pacific Fleet would not have been seen as peaceful, particular in light of the massive attacks being carried out. The Roosevelt administration would have said ouotright that they were about to attack us and we removed the threat, and that would have been that.
What smiling bandit said, and there was complete radio silence among the Japanese armies and fleets moving around in Asia and the Pacific that day and at the same time Japanese warplanes attacked the Philippines and Wake island and Guam, and Japanese troops invaded Malaya and Thailand and seized Shanghai. Those invasions and bombings were already on their way or taking place regardless of the results of the Pearl Harbor attack.
It was impossible for Japan to claim innocence after all that took place that day.
How much advanced warning would there have been? This makes a big difference.
For instance, 24 to 48 hours might have resulted in a worse American defeat. There would still not be American carriers available. And had the fleet sailed, any ships that ended up sunk on the high seas would have been gone for good, instead of being salvageable from the shallow harbor waters. There were only 12 B 17s in Hawaii, though perhaps the 12 that arrived during the attack could have been rushed in a day or two earlier. The only long range aircraft available in numbers were 72 Catalina flying boats, pretty much entirely unsuited to combat against heavily armed formations of warships.
What this amounts to is America launching its surface fleet against an overwhelmingly powerful Japanese fleet, and throwing a handful of obsolete land-based bombers that were later (in the real war) shown to be pretty month worthless for attacking warships.
A more interesting question (to me) is how much warning the Americans would have needed to change the outcome to a victory. It might have been more time than the Japanese themselves had from the decision to launch it to the actual attack date.
Ah, here is a list of the aircraft available at Pearl Harbor on December 7.
The afore mentioned 12 B 17s and 72 Catalinas.
I forgot about the twin-engine Douglas B 18s, an obsolete plane already, but there were 33 of them.
There were 12 Dougles A-20 Havocs, which turned out to be very good bombers – en masse.
3 Martin B-12s, ridiculously obsolete bombers, having lost out in a 1935 competition to the B 18.
26 Douglas Dauntless dive bombers, could be devastating if they got into position unmolested, but they would shooting at 6 carriers.
That’s a total of 156 planes capable of carrying bombs, of which maybe 50 could charitably be called up-to-date.
Contrast this with 315 capable Japanese dive and torpedo bombers.
To add to what others have said, Pearl Harbor wasn’t the first time Japan started a war with a surprise attack and no declaration of war. The Russo-Japanese War of 1904-05 began with a sneak attack at Port Arthur, and the occupation of Manchuria in 1931 was done without a declartion of war in response to a fake Chinese attack staged by the Japanese themselves. An attack without prior declaration of war was expected at the time, the language used in war warnings issued by the Chief of Naval Operations in November 1941 is instructive:
Does anybody know that actual date the Japanese government committed to launch the December 7 attacks? Subtract that date from December 7 and we have the maximum possible warning time for the American military.
Would it have made a difference if it were before or after we had decrypted the Purple 14 part message also on 6 December?
The US could have ambushed the Carrier Striking Task Force with its three carriers, the land based planes and the Pacific Fleet. If they caught them just as they were preparing to launch on the 7th, it was be a slaughter.
Anyway, however they would have done it, had the US taken out the Carrier Striking Task Force, Japan was completely fucked. It had committed its six largest carriers and only had four smaller carriers left. Two out of ten battleships would be gone. Four hundred and forty one planes, and all of those trained pilots. Japan would be hard pressed to recover from this alone. However, their problems would just be starting.
Although it has been naively suggested that because of radio silence, the strike force would not have provided a warning. Nothing could be further from actual military doctrine. The Carrier Striking Task Force would have radioed Tokyo. That contact, however, would have precipitated one of the largest [del]arguments[/del] in the war. Now what the fuck do we do? However, in the immediate situation, Hong Kong would still be attacked, as no one would make a decision fast enough to stop it.
The communication from the Task Force would be received by the IJN. It would sit on this for hours, with internal debates on what the hell to do. Yamamoto would be toast. The IJN and IJA detested each other, and had struggled throughout the buildup to the war.
With the attack on Hong Kong coming in a matter of hours after the scheduled attack on Pearl Harbor, and as it was under the command of the China Expeditionary Army, which was hellbent on taking the war to the ends of the world. It would have taken an imperial order to prevent this, something which would never have materialized quickly enough, even had anyone suggested it.
There would have been little reason to delay the invasion into Thailand.
Other major attacks were under the Southern Expeditionary Army Group, commanded by a peer, Count Hisaichi Terauchi, a former(?) member of the Kōdōha, a radical military group which had wanted military (read army) rule of Japan. How much he would have hesitated is unknown, but it wouldn’t be surprising if the IJN underplayed the devastation of the attack, leading him to press on.
However, assuming he went ahead, there would have been a completely different response than what occurred historically.
Guam would have been attacked and taken, Wake Island would have turned back the first invasion, as it did in 1941. There would not have been a second invasion, though, as the IJN would not have had enough ships.
Several game changers would have occurred. MacArther’s greatest clusterfuck, his inexplicable freeze in the early hours of the 8th simply would not have happened. Knowing that Japan had sailed to Hawaii, and were ambushed would have kept him from whatever dark hole swallowed him for that critical period. The US already had plans in Rainbow 5 to bomb Formosa if Pearl Harbor were attacked, and they would have carried this out.
While the initial landings may not have been prevented, the destruction of the USAAF on the ground would have been prevented. It would have been a fight, one which three fleet carriers and eight battleships would have changed history. If the Philippines didn’t fall, it would have spelled an end to Japan’s war plans. Not only could they not dare attack the DEA, Formosa would be vulerable and the US would have a sub base right off the China South Sea.
The British may not have been able to have saved the Prince of Wales, but they would have not have lost their carriers later, as Japan’s navy was destroyed. The Indian Ocean Raid would not have been possible, so the British navy would not need to retreat from India. With the Royal Navy still there, the attack into Burma may not have gone so far as to cut the Burma road.
Japan would suddenly be faced with the real need to protect the homeland from carrier based attacks. Some IJA air units would need to be recalled.
Japan had bet the farm and rolled the dice. It lost. With no easy way to attack the Dutch East Indies, and subsequently at the mercy of its enemies for oil, the greatest debate of WWII would begin. What the fuck do we do now?
Meanwhile, would Hitler decide to declare war on America? Despite his naval commander’s pushing, knowing that Japan was going to have its ass kicked would have given that leader pause. I’ll let someone else debate that one.
I had long thought the Japanese declaration of war was sitting in the hands of their diplomats cooling their heels outside Cordell Hull’s office when Pearl Harbor occurred. It seems new evidence indicates they debated not declaring war at all until after the attack, and probably the failure to formally declare war beforehand was intentional.
[QUOTE=Wikipedia]
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 … [a]nd they clearly prevailed.”[58]
[/QUOTE]
The declaration document that was eventually delivered to the US after the attack is breathtakingly hypocritical and self-serving when you actually read it. Apparently China provoked them by being vulnerable.
Yeah, I assume the OP means America would avoid declaring war in order to stymie Japan’s intention to have a war? I don’t get it. Japan’s declaration was already enroute to the US government, and certainly Japan’s other attacks had either already taken place or would do so despite losses at Pearl. If Japan declares war and starts killing and invading, the Americans could hardly stop it by holding their hands over their ears and shouting “I’M NOT LISTENING!”
This is one of those myths that just won’t die; the 14 part message was not a declaration of war, it wasn’t even a termination of diplomatic relations. The full text of the 14 part message is here, the final part reads:
All it did was terminate negotiations over China (I particularly like the bit about the US desiring to keep Japan and China at war - as opposed to letting Japan win the war). The actual declaration of war didn’t occur until December 8th, the text is here and is quite clear that it is a declaration of war in the opening paragraphs:
Eh. I linked to that declaration in my post you’re picking for nits. And I did not say the “14-part message” was a declaration of war. What I was trying to say (without having anything solid enough to cite) is that a declaration by Japan was essentially inevitable at that point (unless, I suppose, they made some frantic last-second attempt to stop the process because of the hypothetical in the OP, but I find that implausible).
Just to clarify, it was made on December 8th in Japan, December 7th in the US.
[QUOTE=Boyo Jim]
Does anybody know that actual date the Japanese government committed to launch the December 7 attacks?
[/QUOTE]
December 2nd. Again, that’s Japan time so could be the 1st or 2nd in the US.
And I never said that it was a Declaration of War either but put together that you have a fleet closer to your home port than theirs AND they just broke off negotiations may make a pre-emptive strike more acceptable on the world stage.
According to this page, America could have had two carriers (Enterprise and Lexington) at Pearl Harbor with 5 days notice. The Saratoga had just finished a refit in dry dock and hadn’t even got its planes back aboard. The Hornet had just been completed and had not yet even had its shakedown cruise, and in any case was in the Atlantic. The remaining carriers were also all in the Atlantic – the Yorktown, Wasp, and Ranger --none within range to get to Hawaii in time.
Honestly, the American defeat at Pearl Harbor would have been even worse if the Americans began preparing for the attack on December 2, than the surprise attack actually was.
I take that back – the Americans could have escaped relatively scott-free if they had taken that time to run away – eastward – from Hawaii. It is also conceivable that the Pearl attack would never have even happened had the fleet just run for its life. Japan did launch a couple of float plane scouts before the main attack, and an empty harbor might have led to a cancellation. OTOH, it might have led the Japanese to re-arm their torpedo bombers with conventional bombs and resulted in a heavier attack against ground facilities. Had this happened it would have been a far more even battle, as America did have a couple of hundred (pretty much obsolete) fighters it could put up as a defense.
An interesting follow-up discussion is what would be the fall-out if someone had ordered the US Navy to the East to protect it until it could assemble. The public wouldn’t have been too excited to learn that the US Navy turned tail even if that made the most sense long-term.
I’m very doubtful it would have happened. More likely the Americans would have swaggered out expecting to stomp on the Japanese and instead got their own ass whipped.
Absolutely not. There seems to be a popular misconception that the US was oblivious to the threat from Japan and that the sneak attack came out of the blue with the US never suspecting that the Japanese would attack her. The misconception probably comes from the US propaganda used to help whip up hatred for the Japanese.
The problem with this theory was that the both Japan and the US were actively preparing for war from well before the final decision was made to launch.
On Guam, for example:
The war department issues orders earlier in the week prior to the attack, which instructed the commanders in the Pacific to act as if war were declared. Both Pearl Harbor and the Philippines should have been better prepared.
The problem was that the US didn’t believe that Japan was going attack Pearl Harbor, and certainly not with the size of the task force it sent.
Japanese preparations for the attack had begun in the summer prior to the attack. For the scenario in the OP, was can safely assume that somehow the US had gotten at least part of the plants somehow with enough time to prepare.
These are the reasons for my opinion that more warning would actually have been worse.
Almost all the ships dunk or damaged at anchor were eventually repaired and returned to surface. Had they sailed and been lost at sea, they would have been lost forever.
Referring to my post above, there were almost no aircraft available capable of mounting an effective attack against the Japanese fleet, and no pilots at all with combat experience. A battle between the two fleets would be a surface fleet attacking a fleet with 6 carriers.
Even had the US been able two get two carriers to Pearl Harbor on time, they would have been outnumbered 3-1. And again, the Americans had inferior planes and their pilots had zero combat experience, against Japanes pilots who had something like four times the flight time and substantial combat experience in China.
So, even if a battle had resulted in fewer total American ships sunk, America still would have been worse off because those ships couldn’t be recovered.
Again, you are making an assumption that the US found out at the last moment with no ability to change what it did. That’s OK, but you have to recognize that you are placing an arbitrary constraint.
Had the US found out much earlier, then they could have brought in additional land based planes and carriers from the Atlantic fleet.
The US could also have brought in subs on the attack. If the US threw in everything: land based aircraft, battleships, cruisers, destroyers, carriers, subs, they would have gotten lost some ships irretrievably, but more importantly, the Japanese would have lost at least several of its irreplaceable carriers. The US had a large number of carriers coming online while the Japanese had no ability to build replacements in time.
I think that the psychological factors would have also great, with the Battle of the Philippines being completely different, as I posted above.
It would have been worth losing several battleships forever.