Sidewinder wrote:
So why not negotiate a deal, in which Japan would agree to a cease-fire with the Chinese government- something they could easily get, as Chiang Kai-shek was an obsessive but incompetent boob who wanted to ignore the Japanese so he could continue persecuting the Chinese Communists- and the US would lift the embargo in response? They already controlled Manchuria/Manchukuo, so why the obsession with conquering the rest of China?
Well, after the 1937 fight at Shanghai, totally defeating the Chinese became a matter of saving face and honor, since the Nationalists almost threw them into the sea. Once the win in three months plan failed, well HONOR IS EVEN MORE OFFENDED.... As for the deeper historical reasons, it seems like a pretty straightforward case of China being the only power around militarily weaker then Japan, and big enough to be worth conquering. Japan had wanted an empire ever since the Meiji Restoration, they actually sent ships all over the Pacific looking for unclaimed islands in vain, and by the 1930s the military rulers had the means and an overheating economy to content with. They tried to slowly take apart China, the Chinese wouldn't allow this and stuff snowballed. The hundreds of thousands of dead didn't help make things more acceptable. Japan was so heavily mobilized I think it was clear to the war lords by 1940 that it was now, or never. If they gave into US demands they'd need to demobilize to keep the economy running. Why want an Empire? Well, everyone used to want Empires and Japan hadn't grown out of it or realized how expensive they would be even when they didn't require massive wars. Being a resource poor island group didnt help things.
The US demanded a withdraw from everything but Manchukuo, I can't see the Japanese ever accepting this. However they could have tried to build themselves out of the oil embargo by using Chinese labor to build coal-oil conversion plants and mine more coal. This was proposed, and suggested to be far cheaper than a war. It was rejected because it would have taken years, and in the interim Japan might have been vulnerable. They did after all have to constantly worry about Stalin.
And when Japan itself is being threatened by invasion, why leave all those soldiers to continue persecuting the war in China- a war they thought they'd win in THREE MONTHS- instead of withdrawing them to reinforce the Home Islands' defenses?
Japan did steadily drain men and material out of China after the end of 1942, by 1945 they were pulling back completely in many sectors and moving a lot of troops to defend the coastal regions. Prior to 1944 though, Japan was still fighting the war on delusional terms, it was only after the fall of Saipan and the first downfall of Tojo that they began to act like the situation was as bad as it was. By then, Japan had also lost much of her merchant marine and redeploying really large forces from China could not be done easily. Some Japanese resources did come from southern and central China as well, mainly rice, and the Japanese forces in China would litterally go on short term offensives just to steal rice harvests and so support themselves.
Also the US was by 1944 using China as a base to bomb Japan with early B-29 raids, and US fighters and tactical bombers were at times heavily attacking Japanese coastal shipping, both of which were direct strategic threats. So loss of face aside, real reasons existed to hold onto China. The US made strategic deception efforts several times to suggest that Hong Kong (during the Philippines Operations) and later Shanghai (for Okinawa, intended to be done again prior to invasion of Kyushu) would be US targets.
"This cult of special forces is as sensible as to form a Royal Corps of Tree Climbers and say that no soldier who does not wear its green hat with a bunch of oak leaves stuck in it should be expected to climb a tree"
— Field Marshal William Slim 1956