# Why did the American Aircraft Carriers depart Pearl Harbor shortly before the attack? **URL:** \ **Category:** Factual Questions\ **Created:** [February 23, 2014, 5:07am UTC](https://boards.straightdope.com/t/why-did-the-american-aircraft-carriers-depart-pearl-harbor-shortly-before-the-attack/682005 "2014-02-23T05:07:38Z")\ **Posts on this page:** 9\ **Page:** 3
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [February 27, 2014, 12:49am UTC](https://boards.straightdope.com/t/why-did-the-american-aircraft-carriers-depart-pearl-harbor-shortly-before-the-attack/682005/41 "2014-02-27T00:49:35Z")
> [@TokyoBayer](#): > > As quibble, Japanese sources place the beginning of the planning for the attack prior to Taranto. It had certainly been war gamed by both sides in 1940 and before. Both the U.S. and Great Britain had hypothesized attacks on Pearl Harbor as early as 1928, even noting the probability that the attack would come from the North to avoid detection in commercial traffic lanes. ---
**Author:** ![Dissonance](https://avatars.discourse-cdn.com/v4/letter/d/85f322/32.png) [@Dissonance](https://boards.straightdope.com/u/Dissonance)\ **Post date:** [February 27, 2014, 2:14am UTC](https://boards.straightdope.com/t/why-did-the-american-aircraft-carriers-depart-pearl-harbor-shortly-before-the-attack/682005/42 "2014-02-27T02:14:00Z")
> [@Gray\_Ghost](#): > > All that said, and you’d know this better than me, but have coastal defense artillery ever been proven effective vs a naval raiding party? Effective meaning they repulsed the invasion. I mean, I guess if the ships are deterred from attacking in the first place, that’s the best sort of victory. As you say, deterring an attack in the first place is the best sort of victory. Aside from ones you’ve mentioned, the failed Anglo-French attempt to [force the Dardanelles](http://en.wikipedia.org/wiki/Naval_operations_in_the_Dardanelles_Campaign#The_Battle_of_March_18) in WWI comes to mind. > [@Gray\_Ghost](#): > > The wiki doesn’t list it, but were there significant Japanese naval losses incurred during the Corregidor landings? I have to admit that I’m not terribly familiar with the Corregidor landings myself, but Japan had the advantage of Bataan being only two miles from Corregidor and were able to shell and bomb it for almost a month non-stop before landing. Browsing through the CMH’s volume [_The Fall of the Philippines_](http://www.history.army.mil/html/books/005/5-2-1/index.html) it appears the Japanese landing force took severe casualties getting ashore, but primarily from 37mm batteries and a 2 gun 75mm battery, not the island’s heavy guns. The landings were conducted at night, many of the fixed coastal defense guns had been knocked out during the siege and > [@](#): > > The supply of seacoast ammunition was ample but there was little of the type suitable for attacking land targets and no star shells to provide illumination for night fire. Nevertheless > [@](#): > > At about 0440, as dawn was breaking, small boats believed to be landing barges were seen approaching the Bottomside area of Corregidor. All remaining guns were directed to fire on these craft and on Cabcaben where other boats could be seen. Battery Stockade, with two 155-mm. fixed guns and two more roving batteries, hit the approaching formation with damaging effect. Fort Drum opened fire at a range of 20,000 yards and dropped over 100 rounds on the vessels. Ordered to shift fire to the North Channel, the commander at Drum replied that he could not see any targets because of the dense cloud of smoke and dust over Corregidor. “Just fire in the smoke, anywhere between you and Cabcaben,” he was told, “and you can’t miss them.” > > Though the Americans were mistaken in their belief that they had driven off a third assault, they had succeeded in sinking and damaging many more of the enemy’s fleet > of small boats. Between half and two thirds of the landing craft leaving Bataan that night had been put out of action. > [@tomndebb](#): > > So they had the fire powert of one obsolescent battleship, one battle cruiser, and a couple of heavy cruisers. That does not strike me as much of a deterrent, much less a serious method of opposing a landing. As **Gray Ghost** notes a couple of posts up, land based artillery has a much easier time with fire control than ship based guns. More importantly, this firepower that you dismiss as being that of one obsolescent battleship, one battle cruiser, and a couple of heavy cruisers has one feature that those ships lack: it is unsinkable. Knocking it out requires placing direct hits with large caliber guns. Ships will usually be sunk or abandoned to uncontrollable fires long before every turret is knocked out of action. The amount of coastal artillery on Oahu would make invasion impossible until it was put out of operation; trying to close to the shore with unarmored troop transports would be suicidal. Also note that nobody ever seriously planned, much less attempted an amphibious invasion facing anything remotely comparable to the firepower of Oahu’s coastal defenses. ---
**Author:** ![TokyoBayer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokyobayer/32/13989_2.png) [@TokyoBayer](https://boards.straightdope.com/u/TokyoBayer)\ **Post date:** [February 27, 2014, 2:41am UTC](https://boards.straightdope.com/t/why-did-the-american-aircraft-carriers-depart-pearl-harbor-shortly-before-the-attack/682005/43 "2014-02-27T02:41:51Z")
> [@Gray\_Ghost](#): > > Agree on the torps. But the comment that perplexed me was about bombs. I couldn’t see why they wouldn’t be extremely effective as well. Perceptive question. The modified AP shell bombs were dropped by level bombers and not dive bombers. The level bombers, Kates, could drop torpedoes (about 900 kg.) from a very low altitude because the torpedoes would then go on their own power to the ship. WWII bombers didn’t have the precision to hit ships from level bombers, which is the reason they went with the Val dive bombers, which carried a 250 kg bomb. The modified AP shell bomb was around 900 kg, IIRC. > [@](#): > > Aside, I view a bit of the historiography surrounding America’s resolve in early 1942 to be results oriented. We’ve discussed it before here, but I don’t think it’s as open and shut as many have said that the US would continue strongly after a hypothetical pasting at Midway, especially if the IJN descended on Pearl with their SAG for some recreational shelling, a la the USN shelling Japan in July 1945. I don’t think I’ve debated this particular issue with you, but I don’t see it. They were really hurting for oil at that point. DEA oil wasn’t coming on line as fast as they wanted and Midway burned up a lot of their reserves. The US was learning how to fight them in the Pacific. It would still be a while before the results started to swing more, but the US was very much learning how to fight. The US knew the math, and knew that Japan was burning up carriers, slowly in early '42, but the USN also knew they had tons of carriers coming on line. The original plan had been for the US to lay low for a while, then once the USN had built up strength to take the fight to them. If the US got hit hard at Midway, I think they would have gone back to that, rather than give up. The USN was pissed at Japan after Pearl Harbor and I don’t see them walking away without revenge. I also don’t see the US population just giving up so easily. Remember that America itself was attacked. Japan didn’t have the ability to knock out the US, so if the US stayed low, then Japan couldn’t win. Without getting into a hijack, this is the opposite problem that the US had in the Vietnam war, where the US had made a decision to not fight in North Vietnam. If the battle was going against them in the South, the NVA could pull back and regroup. > [@WheatCat](#): > > No, Yamamoto did not. He was hoping to eventually to inflict enough causalities on the US to make the US tire and negotiate a peace, but he certainly did not expect the US to quit the war within 6 months! > > (Quote from Yamamoto in Wikipedia, taken from Gordon Prange _At Dawn We Slept_): > _Should hostilities once break out between Japan and the United States, it would not be enough that we take Guam and the Philippines, nor even Hawaii and San Francisco. To make victory certain, we would have to march into Washington and dictate the terms of peace in the White House. I wonder if our politicians (who speak so lightly of a Japanese-American war) have confidence as to the final outcome and are prepared to make the necessary sacrifices._ I left my copy of _At Dawn_ several countries ago, so I don’t see where the context of the quote was made. The book is still one of the best on the subject. However, even a casual student of history knows that there was never a snowball’s chance in hell of an invasion of the US mainland, a fact Yamamoto would very well be aware of, so the admiral would not be making a literal statement. Prior to Pearl Harbor, Yamamoto did not predict that the war would end in six months, but like the rest of the IJN, there are indications that he was also suffering from overconfidence from the headly days of the early war, where Japan could do no wrong and the allies could do no right. All of the objectives were taken, earlier and at less cost than even their reckless planning had anticipated. We look at Coral Sea as a draw, with a tactical win for them but giving us the strategic edge, but their navy would have been more positive, with – that they thought – was the loss of _two_ of our carriers, (only one, actually. The US was able to save the Yorktown, but the Lexington was sunk) against the loss of the light carrier Shoho for them. Their euphoria has been described as “Victory Disease”, and in Battle That Doomed Japan, 245. “… the spread of the virus was so great,” the Japanese authors write, “that its effect may be found on every level of the planning and execution of the Midway operation.” There is no doubt that the Doolittle raid was one of the key reasons for the attack on Midway. However, as written above, scope of the attack and the battle plans were the direct result of the crushing defeats the imperial forces had been forcing on the Allies. > [@](#): > > This inference fails because although Japan had beaten China and Russia in 1894-95 and 1904-05 respectively it had been at war with China since 1937-- over 4 years-- with no end in sight as of 1941. What should have given the IJA pause is the whopping they got at the hands of the Soviets at Khalking Gol. [Battles of Khalkhin Gol - Wikipedia](http://en.wikipedia.org/wiki/Battles_of_Khalkhin_Gol) That defeat gave the upper hand to the Strike South faction with the plan to go after the colonial territories of Britain and the Netherlands. The Strike North still wanted to fight the Soviets, and even proposed attacking the USSR simultaneous to the march South. If you are going to go against two Western power, why not a third? The question was not if recent setbacks had altered their thinking but rather where the ideas had come from. I don’t know of any serious historian who doesn’t credit the Russo-Japanese war for the Japanese acceptance of the Decisive Battle Doctrine. The admirals in WWII were young officers during that wildly successful campaign, with leaders such as Yamamoto serving on the front lines. The Russo-Japanese war, and to a lesser degree the First Sino-Japanese war, brought prestige to the then fledging Japanese navy. The Imperial Army saw itself as the successors of the samurai class which had been disbanded in the Meiji Restoration and the abolishment of the feudal domains. The IJA came from the army raised by the key domains of Satsuma (now Kogoshima) in Kyushu and Choshu (now Yamaguchi) in western Honshu and fought under the banner of the Emperor, against the army of the Shogun. (Many leaders of the army came from Western Japan, and even looking at the Big Six of the Supreme War Counsel which decided the fate of the war at time of the surrender, it’s telling that the three members of the Counsel who were diehard militants refusing to surrender were all from Oita Prefecture in Kyushu.) > [@](#): > > Japan was counting on hanging on for dear life, long-term and total. There may have been some fools who felt otherwise at the time, and there may be some media and academic revisionists who now place undue weight on the significance of those fools. There is a world of difference in being prepared to die fighting, to which the Japanese were completely committed, and being prepared to fight, which the Japanese were not. At least not logistically. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [February 27, 2014, 2:50am UTC](https://boards.straightdope.com/t/why-did-the-american-aircraft-carriers-depart-pearl-harbor-shortly-before-the-attack/682005/44 "2014-02-27T02:50:28Z")
> [@tomndebb](#): > > So they had the fire powert of one obsolescent battleship, one battle cruiser, and a couple of heavy cruisers. That does not strike me as much of a deterrent, much less a serious method of opposing a landing. Land-based guns and ship-based guns are like apples and oranges. You can’t compare them one-to-one. Land-based artillery was usually in bunkers, which were harder to destroy than a ship’s armor. Guns on land were not moving and were therefore more accurate than guns on a ship. And a near miss on land would usually not put a gun out of service. A near miss against a ship’s gun might still hit the ship and sink it, along with the undamaged gun. As Admiral Nelson once observed, “A ship’s a fool to fight a fort.” ---
**Author:** ![TokyoBayer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokyobayer/32/13989_2.png) [@TokyoBayer](https://boards.straightdope.com/u/TokyoBayer)\ **Post date:** [February 27, 2014, 3:14am UTC](https://boards.straightdope.com/t/why-did-the-american-aircraft-carriers-depart-pearl-harbor-shortly-before-the-attack/682005/45 "2014-02-27T03:14:49Z")
> [@Gray\_Ghost](#): > > All that said, and you’d know this better than me, but have coastal defense artillery ever been proven effective vs a naval raiding party? Effective meaning they repulsed the invasion. I mean, I guess if the ships are deterred from attacking in the first place, that’s the best sort of victory. I think that’s the most important feature. You don’t attack unless you have enough strength to do the job. In this case, there is simply no way for the Japanese to invade Hawaii, so bringing a large fleet over for just some shelling would be folly. This would unnecessarily expose the fleet to land-based bombers for a minimal psychological gain. Not worth it. Not to mention that the IJN didn’t have the oil reserves for the operation. Midway burned up a year’s worth of fuel by sending damn near everything the could float. > [@Jackmannii](#): > > [At least one Japanese agent in Honolulu](http://www.historynet.com/takeo-yoshikawa-world-war-ii-japanese-pearl-harbor-spy.htm) seems to have had an important role in aiding plans for the Pearl Harbor attack. And note that he was a navy attache. I had forgotten about it, but the Nazi sleeper agent was caught by the US prior to being useful. They did not recruit any of the Japanese living in Hawaii. > [@tomndebb](#): > > Both the U.S. and Great Britain had hypothesized attacks on Pearl Harbor as early as 1928, even noting the probability that the attack would come from the North to avoid detection in commercial traffic lanes. And they had also theorized that the attack would be most effective on Sunday morning. So, what happened several days _after_ Washington sent out a message to on war footing? There is a lot of weight given to the message which didn’t get through in time, but all overseas bases, including Pearl Harbor, the airbases and those in the Philippines had been told to be prepared for an immediate war. > [@Dissonance](#): > > The amount of coastal artillery on Oahu would make invasion impossible until it was put out of operation; trying to close to the shore with unarmored troop transports would be suicidal. Also note that nobody ever seriously planned, much less attempted an amphibious invasion facing anything remotely comparable to the firepower of Oahu’s coastal defenses. Most of the Japanese landings had been unopposed and they were all under the benefit of air cover. An attempted invasion of Hawaii could have resulted in the loss of the irreplaceable experienced Japanese pilots. ---
**Author:** ![WheatCat](https://avatars.discourse-cdn.com/v4/letter/w/258eb7/32.png) [@WheatCat](https://boards.straightdope.com/u/WheatCat)\ **Post date:** [February 27, 2014, 4:31pm UTC](https://boards.straightdope.com/t/why-did-the-american-aircraft-carriers-depart-pearl-harbor-shortly-before-the-attack/682005/46 "2014-02-27T16:31:29Z")
(post #42): > [@TokyoBayer](#): > > I left my copy of At Dawn several countries ago, so I don’t see where the context of the quote was made. The book is still one of the best on the subject. However, even a casual student of history knows that there was never a snowball’s chance in hell of an invasion of the US mainland, a fact Yamamoto would very well be aware of, so the admiral would not be making a literal statement. I have my own copy of the book at hand and I promise the quote is not taken out of context. The sentence before the quote merely identifies it as taken from from a private letter (later made public) to a prominent Japanese ultranationalist. The second sentence after the quote states: _He was warning the far right bluntly that that the United States was not, as certain wishful thinkers believed, a hollow giant to fall and smash to pieces at the first blow._ And on the previous page Japanese Premier Konoye quotes Yamamoto as saying in a 9/40 meeting: _If I am told to fight regardless of the consequences I shall run wild for the first six months or a year, but I have utterly no confidence for the second or third year._ So there is no doubt that before Pearl Harbor Yamamoto expected a prolonged struggle with the US. Now, what would be most revealing is knowledge Yamamoto’s attitude after Pearl Harbor. That should be available in _Miracle at Midaway_ (by Prange posthumously, Golstein and Dillon). That I also have a copy of (somewhere, I think). If I can find it I will post relevant information. > [@TokyoBayer](#): > > Prior to Pearl Harbor, Yamamoto did not predict that the war would end in six months, but like the rest of the IJN, there are indications that he was also suffering from overconfidence from the headly days of the early war, where Japan could do no wrong and the allies could do no right. All of the objectives were taken, earlier and at less cost than even their reckless planning had anticipated. We look at Coral Sea as a draw, with a tactical win for them but giving us the strategic edge, but their navy would have been more positive, with – that they thought – was the loss of two of our carriers, (only one, actually. The US was able to save the Yorktown, but the Lexington was sunk) against the loss of the light carrier Shoho for them. > > Their euphoria has been described as “Victory Disease”, and in Battle That Doomed Japan, 245. “… the spread of the virus was so great,” the Japanese authors write, “that its effect may be found on every level of the planning and execution of the Midway operation.” > > There is no doubt that the Doolittle raid was one of the key reasons for the attack on Midway. However, as written above, scope of the attack and the battle plans were the direct result of the crushing defeats the imperial forces had been forcing on the Allies. All this is quite true, and I would not have been moved to object if it had been posted instead of the insinuation that the US would just cave in after PH. > [@TokyoBayer](#): > > What should have given the IJA pause is the whopping they got at the hands of the Soviets at Khalking Gol. [Battles of Khalkhin Gol - Wikipedia](http://en.wikipedia.org/wiki/Battles_of_Khalkhin_Gol) That defeat gave the upper hand to the Strike South faction with the plan to go after the colonial territories of Britain and the Netherlands. The Strike North still wanted to fight the Soviets, and even proposed attacking the USSR simultaneous to the march South. If you are going to go against two Western power, why not a third? Victory disease even before any victories had been won! > [@TokyoBayer](#): > > The question was not if recent setbacks had altered their thinking but rather where the ideas had come from. I don’t know of any serious historian who doesn’t credit the Russo-Japanese war for the Japanese acceptance of the Decisive Battle Doctrine. The admirals in WWII were young officers during that wildly successful campaign, with leaders such as Yamamoto serving on the front lines. The Russo-Japanese war, and to a lesser degree the First Sino-Japanese war, brought prestige to the then fledging Japanese navy. Doctrine yes, but inference of short war with the US after PH success no. > [@TokyoBayer](#): > > The Imperial Army saw itself as the successors of the samurai class which had been disbanded in the Meiji Restoration and the abolishment of the feudal domains. The IJA came from the army raised by the key domains of Satsuma (now Kogoshima) in Kyushu and Choshu (now Yamaguchi) in western Honshu and fought under the banner of the Emperor, against the army of the Shogun. > (Many leaders of the army came from Western Japan, and even looking at the Big Six of the Supreme War Counsel which decided the fate of the war at time of the surrender, it’s telling that the three members of the Counsel who were diehard militants refusing to surrender were all from Oita Prefecture in Kyushu.) > > There is a world of difference in being prepared to die fighting, to which the Japanese were completely committed, and being prepared to fight, which the Japanese were not. At least not logistically. All true from what I know, but does not address my objection. ---
**Author:** ![Dissonance](https://avatars.discourse-cdn.com/v4/letter/d/85f322/32.png) [@Dissonance](https://boards.straightdope.com/u/Dissonance)\ **Post date:** [February 27, 2014, 6:41pm UTC](https://boards.straightdope.com/t/why-did-the-american-aircraft-carriers-depart-pearl-harbor-shortly-before-the-attack/682005/47 "2014-02-27T18:41:12Z")
> [@Gray\_Ghost](#): > > For those with an interest in WW2 Coastal Artillery performance,[this discussion](http://warships1discussionboards.yuku.com/topic/9005/Coastal-Artillery-works-this-way) at a naval weapons public discussion board looks quite interesting. Oh - oh my, it is a small world. From the fourth post in that thread: > [@](#): > > Even though “he who must not be named” has never admitted it, there were very good reasons warships of all nations generally avoided coastal fortifications during that period. > > BTW, he still doesn’t get it does he, since he has (again) opened another thread on the same topic even after the original was locked down again. I won’t name him, but “he who must not be named” does show up a few posts later; around 5 years or so ago he posted his wildly unrealistic plan for a Japanese invasion of Hawaii on Axis History Forum in the What If section and a number of other WW2 related forums. His imperviousness to logic or reason and dogged determination in the face of reality was quite amusing to watch, I think he may have also authored an even more wildly impossible alternate plan for Sealion. ---
**Author:** ![TokyoBayer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokyobayer/32/13989_2.png) [@TokyoBayer](https://boards.straightdope.com/u/TokyoBayer)\ **Post date:** [March 3, 2014, 2:58pm UTC](https://boards.straightdope.com/t/why-did-the-american-aircraft-carriers-depart-pearl-harbor-shortly-before-the-attack/682005/48 "2014-03-03T14:58:13Z")
> [@WheatCat](#): > > So there is no doubt that before Pearl Harbor Yamamoto expected a prolonged struggle with the US. Now, what would be most revealing is knowledge Yamamoto’s attitude after Pearl Harbor. That should be available in _Miracle at Midaway_ (by Prange posthumously, Golstein and Dillon). That I also have a copy of (somewhere, I think). If I can find it I will post relevant information. I agree that prior to the beginning of the war Yamamoto was opposed to the war. However, by all accounts, he was a loyal warrior and single-handedly developed the attack which brought the US directly into the war. However, he expected that the attack on the US battleships would affect the US morale, which is a major reason that I believe that he also started to think that the US would give give up at some point. If he were truly believing that it was going to be a long, drawn out, fight until the very bitter end, then would he have bothered with a move aimed at morale? > [@](#): > > All this is quite true, and I would not have been moved to object if it had been posted instead of the insinuation that the US would just cave in after PH. Please reread my post. I did not state that it was Yamamoto’s expectation just after PH. That euphoria seemed to have developed in time with the easy success of the first six months. Ironically, he seemed to have forgotten his own prewar statements. > [@](#): > > Victory disease even before any victories had been won! I’m not sure what this comment is supposed to be. Your quotes are showing that the ultra nationalists were expecting a cakewalk. > [@](#): > > All true from what I know, but does not address my objection. Let’s look at your objections: > [@your objections](#): > > Japan was counting on hanging on for dear life, long-term and total. There may have been some fools who felt otherwise at the time, and there may be some media and academic revisionists who now place undue weight on the significance of those fools. Simply no. No one within Japan was planning a total war with the US, with the same degree that Germany undertook in Europe. Your own quotes this time show that many were anticipating the very opposite. Again, my argument is not that the military wasn’t prepared to die for Dainippon, it was that they were not thinking or planning logistics. They did not have sufficient oil capacity, shipping, manufacturing capacity, or other elements required in total war, and not enough to last long enough to endure the several years of conflict. This was never really discussed across the services or at the highest levels of the government. ---
**Author:** ![WheatCat](https://avatars.discourse-cdn.com/v4/letter/w/258eb7/32.png) [@WheatCat](https://boards.straightdope.com/u/WheatCat)\ **Post date:** [March 3, 2014, 7:00pm UTC](https://boards.straightdope.com/t/why-did-the-american-aircraft-carriers-depart-pearl-harbor-shortly-before-the-attack/682005/49 "2014-03-03T19:00:40Z")
> [@TokyoBayer](#): > > I agree that prior to the beginning of the war Yamamoto was opposed to the war. However, by all accounts, he was a loyal warrior and single-handedly developed the attack which brought the US directly into the war. I have not said or implied otherewise. > [@TokyoBayer](#): > > However, he expected that the attack on the US battleships would affect the US morale, which is a major reason that I believe that he also started to think that the US would give give up at some point. If he were truly believing that it was going to be a long, drawn out, fight until the very bitter end, then would he have bothered with a move aimed at morale? I do not agree that morale deflation was the mission of the PH attack, except in that any defeat will lower morale. Yamamoto did not want to commit to unlimited objectives in south Asia with his east flank open to an untouched fleet in being at PH. The mission of the PH attack to eliminate that threat, and open the way for seizing enough US bases in the east (i.e. the Philippines, Wake Is. and Guam) to present a defence in depth that the US would be unable to soon counterattack. Long-term, repeat: long-term, Yamamoto hoped that unfavorable attrition would lead the US to negotiate a peace favorable to Japan. PH was only the first of numerous actions by which it was assumed that end could be reached. > [@TokyoBayer](#): > > Please reread my post. I did not state that it was Yamamoto’s expectation just after PH. That euphoria seemed to have developed in time with the easy success of the first six months. Ironically, he seemed to have forgotten his own prewar statements. An immediate cave-in is the only reasonable interpretation for your repeated emphasis on morale deflation as Yamamoto’s ostensible primary objective in the PH operation. Furthermore, here, again, is the exchange I originally responded to, emphasis added: (reply #23): > [@TokyoBayer](#): > > Although Yamamoto was probably the best military leader familiar with the US potential for industrial output, **he was counting on the US giving in much earlier, prior to the further expansion of their outer perimeter**. One of the reasons given for the attack on Midway was that they had expected the US to give up earlier and the US hadn’t. The Midway operation took place only six months after PH, so any distinction you intend between “much earlier (than Midway)” and “just after PH” is not only unreasonable, but is also too ambiguous to be recognized by anyone not endowed with the ability to read your mind. > [@TokyoBayer](#): > > I’m not sure what this comment is supposed to be. Your quotes are showing that the ultra nationalists were expecting a cakewalk. The comment was only supposed to express agreement with the tone of your own comments on Japanese over-optimism. > [@TokyoBayer](#): > > Simply no. No one within Japan was planning a total war with the US, with the same degree that Germany undertook in Europe. Your own quotes this time show that many were anticipating the very opposite. Yamamoto was certainly planning for a total war with the US, or else he would not have told Konoye he had no confidence for the 2nd and 3rd years. You don’t think he meant that the US could threaten to defeat Japan with less than an all-out effort, do you? Nor do you think Japan would oppose such a threat with less than an all-out effort of its own. > [@TokyoBayer](#): > > Again, my argument is not that the military wasn’t prepared to die for Dainippon, it was that they were not thinking or planning logistics. > > They did not have sufficient oil capacity, shipping, manufacturing capacity, or other elements required in total war, and not enough to last long enough to endure the several years of conflict. This was never really discussed across the services or at the highest levels of the government. All this means is that the Japanese leadership was irrational. They were not the only ones of the era. However, they were not so irrational as to expect that the US would just cave right in, as you would have it. [Previous page](https://boards.straightdope.com/t/why-did-the-american-aircraft-carriers-depart-pearl-harbor-shortly-before-the-attack/682005.md?page=2)