Most people do not know that there were total 20 divisions of German trained Chinese soldiers in WWII. They were fully trained by German advisers, equipped fully in German style uniforms, helmet, and firearms. Here is a photo of them. Even when Sino-Japanese war first broke out, German advisers were working actively on the battlefield on the Chinese side. These German trained Chinese divisions were the elites of Republic of China military, but due to they lacked heavy weapons, they were still no match for the overwhelm firepower of the imperial Japanese forces. Half of them were lost in the Battle of Shanghai. The German advisers were recalled by Hitler after Japan repeated requested it. It officially ended the alliance between Germany and Republic of China which was formed on the common ground of anti-communism in the first place. If these German trained Chinese divisions had German tanks, heavy artillery, etc. do you think Japanese could have had their way in China?
If the Chinese were more closely allied with Germany, we may have seen the Japanes join the Allies. With better weapons and training the Chinese army would have done better, at first, but things would get interesting when Germany and The USSR went to war. The Communists would revolt, Japan would be attacking, and there was the risk of A British attack from India and Burma. The big question is how would the alliances work? Would Japan and China fight their own private war? Or would the Allies get involved. Whatever happens Japan would come out of the war better. Without fighting half the world, and possibly being loosely allied with the US and Britain, at worst, Japan would be forced out of Manchuko. Taiwan, KorEa were too firmly in Japanese control to be defeated by the Japanese alone. More likely, Japan facing a stronger China would take control of the richest Chinese provinces and then force a peace treaty, rather than trying to take all of China.
It would be more like a free for all situation even if Japan sided with the U.S. During 1930s, the Japanese attacked USSR on two occasions near the border of Mongolia and Manchuria. Japan failed both times and thus they decided it is not a good idea to invade USSR, but that put 40 divisions of Russian soldiers on high alert right on the border until the Battle of Moscow. The Russians would never trust the Japanese due to past aggression and the allied forces can't be formed with both of them joined. You have also need to take note that Sino-Japanese war is just a part of the bigger picture. It is not a "private war". Japan was set eyes on the entire world. They had a high government official who planned it all out and presented the plan to the Emperor. "To conquer the world, we must conquer the China first. To conquer China, we must Conquer Manchuria first. To conquer Manchuria, we must conquer Korea first". By the time the full scale war started between China and Japan in 1937, Japan had completed all the previous steps. They would not be satisfied to just having China and stop there. The whole world is theirs as far as they are concerned. There is also the fact China wasn't really united on the same front. Jiang Kai Shek's nationalist party - KMT was having a civil war against the communist party - CCP. Varies of warlords were not really faithful followers of the central government. All of them had their own little agendas. Not to mention Jiang Kai Shek's wife have personal connections in the U.S. in the high ups because she studied there. Would the U.S. choose Japan over China can be a question itself even if China was allied with Germany completely.
Your right that it would be messy. But remember when the Japanese attacked, the Communists and Jiang Kai Shek put their war largely on hold. They didn't support each other, but they didn't attack each other either. The Warlords supported who ever gave them the most. Now before the Japanese attacked, if China was supporting Germany more, Jiang Kai Shek would have a lot better weapons to go against the Communists. They might even get a few thousand 'volunteer' German soldiers to help defeat the Communist threat. This would almost certainly put the Chinese Republic on a stronger footing, especially if it destroyed the Mao's Long March. Japan may be facing a more united China, which would cause some problems. In regards to Russia, they'd given the Japanese a bloody nose and didn't want to waste time on them being more concerned with Europe. Between the two it was more of a cautious live and let live situation. If Japan sided with the USA and Britain, Russia wouldn't get involved, but it wouldn't go and disallow it either. They might actually quietly welcome it as they could move some, not all, troops from the Siberian border. Now for the Japanese, I think you're exaggerating the situation. The 1930's leaders were power hungry, but I don't believe they wanted the entire world. All of Asia yes, but not the world. Now the government of Japan at the time was being led by the nose by the younger officers of the military. the 1937 outbreak of war, wasn't planned by the higher ups, the mid level officers got some support from a few officials and went ahead with the attack. Then their supporters gave everyone a fait accompli. Their opponents were humiliated and lost influence, and the Emperor who appears to have been rather hot blooded, happily went along with the situation. If China could give the Japanese army a bloody nose, the less power hungry officials had a chance to regain control. In our timeline, the Japanese army got bogged down, but they suffered very few large defeats to the Chinese, so they could keep saying 'just one more push, keep going and we'll succeed.' In this timeline, if they suffered some serious set back, they can't say that, so calmer voices may prevail. As for the US, yes there were ties between China and the US, which is one reason the US was sanctioning Japan. But there were a lot of voices calling for complete neutrality, which is why there were only sanctions, not an actual war until Japan attacked. If the Chinese are allied to the Germans, while there will be some people who support the idea, many, many more will see supporting China as bringing them into the European mess. So I'm not sure how much support China will get, but it likely won't be more than OTL.
The funny thing about the Chinese civil war between KMT and CCP was that, even the Chinese Communist forces had German military advisers amongst them, and one of them were put in the position to command the frontline troops. Jiang Kai Shek's German advisers were not really in combat, but they were helping KMT to train troops. The goal was to have 40~80 German trained, German equipped KMT divisions, but of course it didn't complete when Japan invaded. The German advisers however were giving lots of insight to Jiang Kai Shek during the Battle of Shanghai, that almost 3 months long major campaign involved total a million troops from both sides. You are wrong about the civil war completely stopped when the Japanese attacked. Jiang Kai Shek was telling everyone that in order to stop foreign aggression, the civil war must be taken care of FIRST. That is why he even flew to the frontline to oversea one of the warlords in combat against the communists. It ended up that warlord kidnapped Jiang Kai Shek and force him to agree to stop the civil war immediately in order to prevent China being taken over by foreign aggressors. If wasn't for that warlord, Jiang would still be fighting CCP and continue to order his forces to retreat instead of fighting against Japanese. Japan was a major naval and air power in WWII, but their ground troops was not on the same standard against European powers such as the Soviets simply because Japan was an island country, and they put major effort to build ships and planes instead of tanks. They got their asses handed to them by the Russians twice because they were overwhelmed by Russian tanks in a ground war far away from any possible of naval support. Japan however did pick a great time to invade China, as China was in a continuously decline for the past 100+ years, and it was in a bloody mess of a civil war (almost free for all) at the time. The Germans were getting some special alloy from the Chinese which I believe were used to make their tank armor. The Japanese ensured the Germans that those material would still be delivered to Germany if they cut their tie with the Chinese. That never happened. Germans lost key material to enhance their high grade steel armor for tanks when they abandoned China. Another thing is, the Russians took over Germany's position in helping the Chinese after the Germans pulled out. Russians saw Japan as the aggressor ever since the Russian-Japanese war during Russian Empire era. They even had pilots in China directly fighting against Japanese until they were ordered to move back to Russia to help themselves due to German invasion. The U.S. took over Russia's position to help China in the form of the Flying Tigers. A paid mercenary air group featured with shark painted planes. Yep, it would be a total weird situation if Germany stayed as an ally of China.
I did not know this. Your post asked what would happen if the Chinese had German artillery and tanks, I was taking it to it's logical conclusion that the Germans gave full support to the Chinese. If Germany had done this, then many things would have changed, one such being more German advisers and volunteers, the other possibly being an earlier start up. My bad. It's been a while since I've studied this period. Agreed. Yes, so this could be one reason in this timeline for the Germans continuing to support China. So what do you think would happen if Germany had continued to support China?
If Germany did support China all the way, and if China was able to manage to pay for several division of German tanks ( I believe several divisions of tanks would be the max they can support, due to fuel problem... China didn't find any oil at least a decade after WWII), Japanese would have had a hard time dealing with them. Even though the tanks would be most likely PzKpfw I and PzKpfw II, very little chance to have PzKpfw III and above, they would be giving the Japan army (mostly consisted of infantry and light armor) a run for their money. I thought it over and over... For the most part, if Germans remained an ally of China, here is one of the possible outcomes 1. China continue to fight against Japanese invasion. 2. Japan continue will not touch USSR due to got their asses kicked twice. 3. Germany will still proceed to invade USSR 4. U.S. would still be siding with UK against Germany. 5. U.S. might still place embargo on Japan as it was in the history due to the fact the embargo was there for the sole purpose of protecting the U.S.'s own interest in the region. (Japan's conquest of China started to hurt American business with China and entire Chinese coastline was blockaded by Japan). Thus it will still lead to Pearl Harbor and the U.S. entered the war against Japan. It would be more like a free for all situation - China vs Japan vs U.S. vs German vs USSR In other words, still pretty much the same situation lol...
