I can't go through the whole thread at this time, having just noticed it for the first time today.
@Alexniko the OP:
Let me just stipulate, as might be actually disproven by better war nerds than me, that the sweeping doubled down Banzai attack on Hawaii is feasible--IJN let us say can in fact land two divisions in the main Hawaiian islands, first with a nutcracker invasion of Oahu which once secured, is the base to fan out to systematically take the remaining nearby islands. Note that if the IJN does not double down further and immediately attack Midway, simultaneously in fact, the rational thing for the USN command to do is order those units there to remove all the materiel they can, sabotage the rest as much as possible, and board what ships they have currently and withdraw back to continental US Pacific ports (by Great circle, bearing in mind this is December and Alaska is a poor choice, Seattle is closest, then down the coast to SF, SD and Panama). They might have to engage the IJN on the way back but their orders are not to seek that but retreat and regroup at US ports. It is known by then that the Philippines and other US assets are under attack too, so their orders dither between trying to defend them versus a cut and run calculation. So a lot of your assumptions the USN gets ground up finer and finer in the Pacific are predicated on mindless refusal to think defensively; bad luck will trap a lot of US forces where they must defend hopelessly or surrender, but faced with this massive defeat in Hawaii the USN is not going to sit around in Midway to be further whittled down.
Anyway exact magnitudes of losses in 1941 and '42 are not the main thing to consider here. (You didn't even bother to point out loss of Pearl Harbor means loss of those forward shipyard equipment, and in fact that unless US forces take initiative to sabotage everything first, the Japanese capture both this valuable equipment set and any USN vessels, Army airplanes, etc, not scuttled or sabotaged, and they can over time and given materiel, do what we did, use the yards to salvage any scuttled vessels and to maintain their fleet, augmented by captured US hulls!)
So--it is a question of whether this is such a blow to morale on the US home front that US domestic politics forces FDR to sue for terms or drives him out of office to be replaced by some successor. Congress can in fact pull the plug on any administration's war plans if it fails to win majority support in the houses.
But I think you are grossly incorrect in arguing this will in fact happen! You may well be reasonable in saying this is what the Japanese war planners will
believe will happen--in fact OTL they believed that the lighter blows they did in fact strike would be sufficient to achieve these results.
Here's the thing. There is not a damn thing the Japanese empire can do to attack the US in its continental stronghold. They can try to invade Alaska, which is tough because of its tough weather and terrain, and if taken in full, it is then up a rough Canadian coast from Seattle; Canada would of course be an ally and thus the entire Puget Sound region is a consolidated defense using US and Canadian assets--of course Canada is no naval superpower, but with US aid they can build stuff and train men as fast as the USA can, just fewer in number. The Canadian approaches to the Pacific NW will be contested!
Or they can try to strike far across the Pacific, direct at the other elements of the US coast and Panama. Indeed the USN is badly decimated, cut almost in half, and the defense of this coast will be nerve wracking for some years to come. An IJN strike force, carrier based or conceivably some giant seaplane launching submarine, can pop up anywhere (the USN can hardly patrol the approaches very well).
Except that airplanes based on land have a fair depth of range, and the inability of the USN to patrol the US coast and west end of the Panama Canal by task force will be supplemented by USN and USAAF patrol flights out to sea, soon incorporating recent inventions like airborne radar. Higher priority than OTL will go to expanding the Goodyear manufactured patrol blimp fleet and building bases for them on the Pacific coast and in Panama; these airships were actually quite effective at forcing subs down and spotting ships, and gradual improvements in them can give impressive range--albeit maybe landplanes will always by this late date in aeronautics outclass them for surface ship patrol missions. Either way, HTA or LTA, CONUS, Pacific Canada, and Alaska will be screened by aircraft, and every attempt to use the planes to attack IJN vessels of any class that are found in range will be made. The IJN then cannot in fact approach the shores and ports of North America with impunity--possible ability to get an Alaskan foothold depends on diverting major force to there ASAP, before the Yankees can make the planes and blimps.
Behind this aeronautical screen CONUS has not only a massively larger industrial complex built, it has vast potential to expand it, and most resources needed can be found right there in the USA. Others in short supply in North America can be gotten from allied controlled British colonies and other colonies the British have occupied.
Presumably in 22 pages the whole question of Germany and the European theater has come up.
There is no default reason to doubt Hitler will do FDR the favor he did OTL of gratuitiously declaring war on the USA, solving the possible political question of whether to try to persuade Congress and the nation to DOW the European Axis powers.
OTL, in late '41 and early '42, the situation looked grim for all the Allies. Conventional wisdom said the USSR would surely collapse fairly soon, and then Hitler (and possibly, in a partition deal, Japan) would have access to formerly Soviet resources and not be drained on that front by more than declining partisan resistance if that. That would also put Hitler in the position of being able to strike directly at British India and the Middle East generally; presumably Turkey would join the Axis or die. In the Pacific and Indonesia, the Japanese were running wild, in China the RoC and Communist resistance to Japanese occupation was in retreat. All Southeast Asia would be falling into Japanese hands quite shortly and as you say, Australia and NZ under threat of invasion and perhaps conquest. Then Singapore fell too and Burma was invaded and IJN elements started to poke their nose into the Indian Ocean, a sea where the major British bases were on the shores of an India seething on the edge of rebellion before the war, with colonial Africa full of natives developing their own anticolonial movements--the late Russian invasion putting Stalin into bed with the British and now the USA at least would mean Communist activists would be ordered to cooperate with colonial authorities and hold off on active subversion, but they remained a long term threat to British rule, unless Britain were prepared to give up on that.
BUT--what the Japanese, and Hitler for that matter, failed to reckon with was that the Allies were motivated to tolerate ongoing losses, in the long term reckoning that eventually, the superior resources of these powers would halt Axis expansion and start to push back, and once that day of turning point came, there would be nothing objective the Axis could do (barring the science fictional invention of some wonder weapon) to prevent being eventually steamrollered. If the German U-boats and surface raiders could have choked all Atlantic commerce, maybe Britain could be forced out of the war--but the RN was doing well in the Battle of the Atlantic against Hitler's worst efforts, and now the untouched USN Atlantic fleet had the gloves off. As noted, the defense of CONUS could be managed on the Pacific with no fleet elements whatsoever, whereas some would surely be evacuated and saved.
The OTL prioritization of Europe over the Pacific would still be good policy. All the US has to do is hold off actual invasion of the Pacific shore, which is extremely hard for Japan to attempt and relatively easy to defend against, and start building new ultramodern ships with design informed by recent combat experience. In the Atlantic, the USN was mainly in the business of escorting convoys--failure to accept that led to the "second happy hunting time" for the U-boats on the US Atlantic coast, but eventually the Navy, resistant as they were to being stuck with this inglorious task, worked out quite effective defenses driving the German subs largely to ground. Clearly US naval assets being rebuilt could be earmarked for an eventual breakout into the Pacific again, in concentrated force.
There would be no reason for Americans to lose morale to the point they give up on the notion that eventually US forces shall prevail, and take back all losses, and eventually roll on over other Japanese conquests and arrive to force the Home Islands to come to US dictated terms. There was not a damn thing Japan could do to knock us out.
As for the war not being fun...war is war and people had much to fear, in the form of beloved young men never returning home or being crippled.
But your idea that rationing was demoralizing for instance fails to take into account that prior to the war breaking out, the USA was still crippled by hangovers of the great depression. Whereas between the draft and volunteerism depleting the male traditional workforce and a huge surge in demand for a high paced war production economy on the home front, what "rationing" actually represented was a guarantee of minimum food and other needs met (housing was a severe wartime crisis, but people made do) that resulted in a large number of people eating better than they had in a decade or more, and no one faced starvation any more.
US production levels were such that rationing cut into luxury, but the allocated levels, maintained in fact by adequate production, were quite generously nutritious. (The British public, under more severe rationing, also objectively ate better, in the sense of a medically balanced diet, than they ever had--wartime children famously were quite healthy).
What "rationing" meant actually was better equality between citizens than ever before, shared inconvenience, no severe hardships for anyone.
Meanwhile, in North American security, the authorities managing the war effort could quite comfortably balance the claims of war priority versus civil content and morale, and the more organized and developed the war economy was, the more scope there was for both guns and butter. The USA did not push anywhere near its limits OTL, and the worse Pacific situation does little to change that balance.
Knowing then that the war plan is to defeat Hitler first, and then turn to stomping out Japan in due time, all your scenarios of morale-wrecking losses would have little bearing on American homefront morale. If the turning of the tide in Africa, the Med, and the Soviet front that late 1942 brought OTL comes soon enough, that will be where the
good war news comes from, and progress against Hitler is warrant enough to justify the US home front belief that the USA and allies will prevail eventually. It might not be until say 1950, but meanwhile, aside from the privations, risks and horrors of war itself, even American servicemembers are living better than many of them did in the peacetime Depression years. There is a lot more to hope for.
Financially for instance. All these newly built war production plants hired people for wages, and with rationing, there was little to spend the accumulating surplus money on. But the government wanted people to buy War Bonds. Well, why not? They couldn't do much else with their wages anyway, with the prices of rationed goods kept in line with wages by the wartime rationing/price control administration. Worst case, the money might go poof in runaway inflation or some other postwar financial mess. But in fact, the US government had quite credible means of paying off the war bonds, no matter how massive they became, and in the short run it gave the military-industrial complex essentially a blank check to do any damn thing. Like the Manhattan Project for instance. Postwar, those bonds were the foundation of fiscal security and fed into the massive consumer demand boom which fed back to strong job markets at increasing wages.
The longer the war drags on, the larger these negotiable and solid nest egg investments are for postwar. Assuming people have some confidence the US system will not renege on wartime promises--and they are still electing governments democratically on schedule all through the war--they have little to fear, beyond ongoing losses of loved ones to be sure.
Will American citizens in the middle of the war know all that? No, a lot of people did worry that postwar the economy would go pear shaped again. But I think the longer the war goes on, the more of a general mood of solidarity would prevail among most US publics. Everyone has been well taken care of so far, there is no reason to fear any sudden worsening, the worst thing is fearing the message saying some son, boyfriend, husband or father is not coming home, or coming home crippled. But that is blamed on Hitler and the Japanese war lords, not on domestic wickedness.
No, if we stipulate the IJN can Mary Sue their way into even more sweeping and crushing control of the Pacific without bankrupting themselves, and prevail so terribly, I don't think that changes the
long term balance of power at all. The Big Three Allies all can survive, and all will be turning back to the Pacific with redoubled and war-seasoned massive force by and by, at a moment and in a manner of their choosing, and no one in the USA, Britain or Soviet Union will want to pull the plug before Japan is well and truly defeated, nor can Japan parley these massive early conquests into permanent, sustainable strength to fight off the USA, Soviet Union returning in force to the Pacific front, and remnant Commonwealth/Empire forces. If they have to retake Australia, NZ and Hawaii, so be it.
The longer the war goes on, the earlier in it (relative to eventual V-J day) the eventual success of the Manhattan Project becomes relevant. Probably the Trinity test is well before a B-29 (Silverplate version) can reach any Japanese Home Island city, so the sober calculation will be that a decent inventory of the damn things be built up first, say 20 or so, and then the USN will set about using them in the island hopping program--just nuke Iwo Jima's major bases wholesale, and then invade to mop up. Horribly, US forces will learn sad lessons about fallout contamination the hard way, and after tragic and avoidable losses, strategy for use of atomic bombs effectively as a force multiplier will be shaken out in light of this bitter experience.
Then perhaps, seeing their doom approaching, with the Americans setting off these monster bombs often enough to dissuade anyone from arguing we only have a limited number of them, it will be Japan that sues for terms. And perhaps, after such a long war, the Allies will grant them--provided they are sweeping and final enough. A face saving difference between "unconditional surrender" and something that is de facto amounting to the same thing can be found, if the Allies would really like to spare themselves another year or two of pointlessly costly war if a victory good enough to call total is at hand.
Or they might not surrender, in which case it is a boat race between Soviet based land offensives against the overseas deployments into China versus USN island hopping converging on the home islands and cutting them off with a commerce raiding noose, soon supplemented with one city after another going the way of Hiroshima/Nagasaki OTL. At some point, if no Japanese authority cracks and offers terms, their machine will crack and break down anyway. By then the Manhattan Project improvisations for fissile material production will have shaken down and been expanded in the most cost effective way and the USA has got a reliable A-bomb production line going, along with incremental improvement in the B-29 or perhaps earlier deployment of the B-36 to drop the things.
One way or another, Japan is going down eventually. You can argue a heavier blow earlier means this happens later and with more widespread damage done.
This idea you have that it depends on cracking US civil morale with a heavy enough blow to daunt is exactly how all the Axis leadership thought, and whether it was in Britain, in Russia or the USA, they never seemed to grasp that going too far would call forth resolution to see the war through to victory, their having proven they could not be lived with peacefully. Nothing you suggest seems to meaningfully change that equation!