The entire Chinese territory except Manchuria and Taiwan obviously (both nationalist controlled and communist controlled) is ISOTed from one day before the start of the Second Sino Japanese War in 1937 to one day before the start of the First Sino Japanese War in 1894.
What's the outcome?
All nationalist forces (including regional warlords) have approx 1.7 mln troops while the communists have approx 640,000.
Subsequently, Japan captures Taiwan but is incapable of taking over Korea. The ROC army is too strong for the Japanese to crack with it's German trained divisions being particularly fierce opponents. As a consequence, Korea remains as a client state of China.
Some questions:
1. What does Japan do given that it's plans of expansion in mainland East Asia are defeated? Does it concentrate somewhere else or maybe abandond militarism altogether?
2. How does arrival of China with it's knowledge of ww1 impact Europe? Does a major war in Europe still break out? Whom does China ally itself with, if anyone?
3. What is the international position of China 20-50 years after the ISOT?
4. What tech available in China in 1937 is of importance to Europeans? I guess radio and aircraft would be quite valuable. Is there something else of value?
stevep --------- Japanese capture of Taiwan actually is not a certainty. We might tend to think so, because we're used to Japanese dominance at sea, and it seems natural and China could not even try to compete navally in the second Sino-Japanese War, but Nationalist China did have a few warships that were probably twentieth century technology, so they actually might be able to constitute a viable flotilla helpful in protecting the Penghus/Pescadores and Taiwan from any Japanese invasion fleet of 1894 and 1895. Japan did not bother with either until 1895, then it was the Penghus/Pescadores, and occupied Taiwan and suppressed rebellion there only *after the peace treaty of Shimonseki. Additionally, Nationalist China had an Air Force in 1937, which Japan in 1894 completely lacked. If it could identify flat fields to safely land on Taiwan and could operate just a few aircraft, that would be a game changer. Even just some transport aircraft or modern transport ships shuttling over some of the regime's modern infantry and a decent supply allocation could be adequate to repel any invasion.
For the Korean and Manchurian battles, I guess Korea, and the footprint of Japanese occupied Manchukuo would be old Joseon Korea and Qing Chinese Manchuria. So Japan would be doing fine initially against local forces. But it is when 1937 Chinese Nationalist forces come driving across the Great Wall, or marching, or get ferried in boats or flown into Manchuria and Port Arthur and Korea, that they show their superiority to the Japanese. Their only challenge, as in Taiwan, is getting into position while keeping adequately supplied. Here again they're possessing an Air Force is a boon.
But with their Air Force assets they have to be careful and listen to their technical experts. They need mechanics at the ready and workers ready to landscape proper airfields, because they don't want to wreck all their airframes prematurely for lack of suitable places to land.
1. What does Japan do given that its t plans of expansion in mainland East Asia are defeated? Does it concentrate somewhere else or maybe abandond militarism altogether?
It puts militarism/expanionism on pause, except possibly against the Spanish Philippines, until it strengthens itself more, gets more even with the technology, and finds a weaker enemy.
2. How does arrival of China with its knowledge of ww1 impact Europe? Does a major war in Europe still break out? Whom does China ally itself with, if anyone?
Unless you exclude books news, knowledge, and the foreign concessions there will be a huge future foreign community in Shanghai and elsewhere. "news from the future" will change everything. WWI "as we know it" won't happen, but other, preemptive wars and repressions and assassinations, would start. China would wait and see if it wants to participate in any wars besides making sure to win against Japan.
3. What is the international position of China 20-50 years after the ISOT?
Hard to say, depends on its internal cohesion - it will be much harder for external bullying to be a primary driver of failure or trouble.
4. What tech available in China in 1937 is of importance to Europeans? I guess radio and aircraft would be quite valuable. Is there something else of value?
Medical knowledge. Advances in theoretical science, even if only in books. Possibly some audiorecording technology and sound filmmaking and color film-making technology and certainly libraries of "talkies". Cinematic special effects and "fight by wire" from Chinese Wuxia 1920s and 1930s martial arts proto- "kung fu" films.