....Books focused on individual campaigns [of China's WWII] are just now being written and published. Peter Harmsen (previously a reporter with AFP, Bloomberg, and Financial Times) is at the forefront of the effort to tell the story of China’s experience in World War II from the perspective of the soldiers who fought it. His two books on the subject, Shanghai 1937: Stalingrad on the Yangtze and Nanjing 1937: Battle For a Doomed City, are not only meticulously researched, but are gripping reads as well. And if we are fortunate, Harmsen will continue writing these histories. A golden age of Chinese military history is still far away, but if books like Harmsen’s continue to be published, a golden age of China’s World War II history may be just around the corner.You can read the full thing here.
The battles for Shanghai and Nanjing are a proper place to start this effort. The campaign along the upper Yangtze was one of the most destructive of the Second World War. The battle began with the systematic demolition of Shanghai, then (as now) the central hub of East Asian commerce and Chinese finance. The Chinese committed about 750,000 soldiers to the campaign; the Japanese deployed around 250,000. By the fifth month of operations Japanese casualties had risen to over 40,000 wounded and dead; the Chinese lost over 200,000. The Japanese would end their campaign with the conquest of Nanjing, China’s capital, and inflict upon its citizens one of the most horrific massacres of the 20th century. Having lost their best troops along with the capital, the Nationalists would begin their long retreat to Chongqing, steeling themselves for years of grinding warfare. For the Japanese the conquest was a bitter victory. They had won, but at the cost of being irreversibly enmeshed in a war they never wanted, one step closer to their empire’s total destruction....
I emphasized in this review essay that from a strategic perspective the most interesting--and perhaps most puzzling--thing about these campaigns is why they happened at all. Unlike most of the battles fought during the Great War of Resistance, Shanghai was a battlefield chosen by the Chinese. The Japanese decision to meet the Chinese challenge in Shanghai was also the product of long debate and careful assessment. Unlike so many other battles fought at this stage in the war, the decision to make Shanghai the centerpiece of Japan's war effort was made in Tokyo, not by impetuous officers in the field. Why did each side decide to commit so much to this battle?
I provide a few potential answers in the essay, so you will have to read it for the full account. However, I had to edit out a few arguments for the sake of space and flow. One is Hans van de Ven's contention that Chiang's decision to fight in Shanghai instead of in the north had everything to do with China's internal politics and the trouble Chiang had keeping an unruly pack of warlords together.  Ven points out that (with the exception of the Guangxi clique's powerbase in, you guessed it, Guangxi), Chiang had a much firmer hold on China's east and south. The further away you went from the Guomindang's original home in Guangdong and its new headquarters in Nanjing, the less power he had. The warlords closest to the Japanese advance were the flakiest. They were easily intimidated by the Japanese, and highly distrustful of Chiang to boot. One of them, Han Fuju, would indeed end up abandoning his troops and the entire province they garrisoned at the first sight of the Japanese assault. In the upper Yangtze delta Chiang did not have to rely on weaselly characters like Han Fujin to defend or seize critical objectives. Thus by forcing the Japanese to fight in Shanghai Chiang was forcing them to fight in the one place where they could not tear away his auxiliary troops and supply lines through political maneuver. Had Chiang marched his best troops towards Tianjin, on the other hand, this would have been a constant fear.
Sarah Paine suggests in The Wars for Asia that Chiang's decision to focus on Shanghai as a mistake. Shanghai was defended by the Imperial Japanese Navy. The naval flotilla moored just outside the city was one of the few things that stopped the Japanese from being overrun in the first week of the battle, and the Chinese attack on Shanghai was thus an attack on the Navy's assets there. Those who have read about the run-up to or the conduct of the Pacific War will be familiar with how dysfunctional relations between the Imperial Army and Imperial Navy were. The Navy and Army were rivals for prestige and material; every war on the continent meant tons of steel not spent on upgrading the fleet. The Navy's automatic response to almost every operation on the mainland was disapproval, ranging from skepticism to outright hostility. Paine suggests that Chiang should have taken advantage of this natural cleavage in Japan's highest bodies; instead he decided to attack the Imperial Navy, committing them to a war they would have otherwise preferred to end quietly. 
It is hard to tell how plausible this argument is, for there simply are not any books that narrate the Tokyo war-room debates of 1937 with anything approaching the detail that the books covering the debates of 1941 provide. (Of course it is possible there is such a book, and I have just not happened to have heard of it; if so I encourage you to sound off in the comments. But my search has been fruitless thusfar). I am inclined to agree more with Ven than with Paine. If Chiang had no choice but to fight, then Shanghai was where the fight had to be. As I discuss in the main essay, this was necessary to convince coalition partners (e.g., the Guangxi clique and other warlord groups, the USSR, the Communists) to commit to the war, and as argued here, as long as Chiang's best troops were holding the line, it was also necessary to keep the fight in territory which Chiang controlled. Chiang's mistake was not to fight in Shanghai, but for how long he insisted on fighting there. One wonders what might have happened if the mass of troops funneled into Shanghai in September had been sent instead to man the Xicheng Line defense works (modeled on France's more famous Maginot Line) instead. The disastrous retreat from Shanghai might have never happened. Once Japan committed its full industrial might to the war the capture of Nanjing was probably inevitable, but a more controlled and ordered defense of the city and the Xicheng Line might have blunted some of its worst features.
 T. Greer, "Review: Shanghai 1937 and Nanjing 1937," Strategy Bridge (20 April 2016).
 Hans van de Ven, War and Nationalism in China, 1925-1945 (New York: Routledge, 2012), 170-209.
 Sarah Paine, The Wars for Asia: 1911-1949 (Cambridge: Cambridge University Press, 2014), 132.