U.S. military analysts and historians craft 10 scenarios, of varying believability, of "where could Japan have won," ranging from never having attacked U.S. to a super storm right before invasion of Kyushu.
Quality of scenarios vary (10 different authors), many with heavy technical information incl. lists of units and obscure commanders; this work not for generalist readers.
the 10 points of divergence are:
`Japan attacks USSR rather than USA
`USA drive West across Pacific dictated by political pressures rather than military needs and suffers heavy capital ship losses
`Yamamoto launches a third strike at Pearl Harbor
`Japanese fleet performs unexpectedly well at Coral Sea
`Two historical instances at Midway of US forces locating Japanese fleet do not occur; US unable to locate the Japanese carriers, Japan wins Midway
`Japan invades Australia
`Japan goes deep into India by land
`Japan wins Guadalcanal
`Japan wins Leyte Gulf
`Japan refuses to surrender and the Kyushu invasion, with typhoon, is devastating to US forces
3-4 of the scenarios envision the US suing for peace, with Japanese holdings enlargened and perhaps the Philippines returned to the US as part of the diplomatic close
2-3 say even a Japanese victory at some turning point would have only delayed eventual outcome by a few months
1-2 point out nuclear weapons sort of sealed US victory, although it may have delayed
1-2 suggest Japanese victory would have placed it weak in a Cold War scenario
Scenarios are generally believable. There is some tendency to transpose Cold War events with a Japanese victory context (actually, things would go differently if the Axis had won WW2).
the most aggressively "Japan victorious" scenario posits Japan gaining Indochina, making major advances in China, and getting the US to sign a peace treaty. cf. PKD [b:The Man in the High Castle|216363|The Man in the High Castle|Philip K. Dick|http://d.gr-assets.com/books/1347388495s/216363.jpg|2398287] where a combined Axis victory leaves the Japanese installed on the West Coast. ironically, this is one of the most read and highly well-regarded alternative fiction novels.
generally historians, fiction writers, and military analysts agree that Japan was playing for a measured victory in WW2 and ended up losing it all. this leads the modern viewer to wonder why Japan attacked the US at all. perhaps the past can never be understood by the present ?
I. Russo-Japanese War?
or "Khalkyun Gol Battle" in Russian
>Soviet BT-7, predecessor to the famed T-34 that shocked Hitler. designed 1935, weighing some 14.0 tons, 45mm L/45 cannon, 6 - 22mm of armor (presumably 6mm on rear, 22 up front), crew of 3, 450hp engine= 50 kph offroad, 70kph on roads, some flaws noted with flammability (a cold weather tank). was engaged by infantry with Molotov cocktails and specialized anti-tank guns. Soviets had some ~500 at Nomonhan.
Japanese type 89 tank, after adoption of 'Strike South' school, was used until end of war (unlike Soviets, who invented bigger and bigger tanks). Japanese had some ~135 of this or smaller tankettes, designed 1927, weighting some 12.8 tons, 57mm cannon + two machine guns 6.5mm calibre, crew of 4, 120hp engine, armor 6-17 mm, top speed: 26 kph. = severely underpowered by ww2 standards.amateurs talk tactics; professionals talk logistics. 'Nomonhan, the graveyard of reputations' meant the end of the career for IJA generals, but put Zhukov in place as the head of Red forces against Germany. Zhukov's decision to mobilize 2000+ supply trucks is regarded by military historians as the critical decision for victory, whilst the Japanese emphasis on 'spirit' or 'morale' is generally downplayed in the modern world.
a proposed "Japanese assault on the Soviet Union" seems one of those justifiably 'large' decisions that could have resulted in a dramatically difficult outcome for the war. would the Soviet Union have been able to survive a double- assault from East and West? if not, and the USSR collapsed, would the Western democracies UK-US-Netherlands be able to stand up to the Axis Berlin-Tokyo without any dramatic power between them? the resulting "Cold War" would then be between the Axis and the West, but presumably, the West would have still had nuclear weapons by 1948.
this seems one of the sort of 'alternate history scenarios' that at first sight seems to make perfect retroactive sense, but in reality considering force-dispositions at the time is pretty idle speculation. the Japanese had little tank-industry, they did have huge battleships. accordingly, the strike south faction had all the weight of material logic on their side. putting this issue aside, even if the Japanese with their slow tank designs (above) did attack the Soviet Union, the USSR probably could have held on in the Urals for some time, as Siberia is relatively economically unimportant and consists of vast amounts of territory.
II. India liberation ?
the India liberation scenario is the other 'grand strategy' level matter that may promote systematic evaluation. if S. Chandra Bose had sent in 'pan-Asian' liberation forces to India and captured broad support, the presumed outcome is a severe degradation of British Empire war-making capacity. Indonesia was never recovered after it was liberated by the Japanese, and possibly India too would have been boldly committed to an anti-UK cause if it actually had military divisions and such under its control.
this outcome presupposes the possibility of an Axis victory in the Caucasus. but once again we deal with the reality that the US atomic bomb program was considerably far more advanced that any Axis counterpart. we can imagine scenarios with the war prolonged to the early 1950s, but ultimately it is difficult to see how either Berlin or Tokyo would have been able to counter repeated atomic strikes.
ahistorical / allohistorical writing invites questions of 'are we living in a predetermined world?'