Anti-communist writers Jung Chang and Jon Halliday assert in their highly controversial 2006 book Mao: The Unknown Story that the Nationalist general Zhang Zhizhong was a Soviet agent who, following the Marco Polo Bridge incident in July 1937, had been tasked by Stalin with escalating the already tense situation with Japan into a full-scale, all-out war.
Stalin ordered this, Chang and Halliday maintain, because he (quite reasonably) feared Japanese aggression against his own country and wanted to draw China and Japan (both of which were hostile towards the USSR) into a costly war with one-another in order to weaken them both. This certainly was the approach he took towards Germany in 1939 after the failure of collective security, so it's not without precedent (or postedent?). In addition, Zhang himself was a strong communist sympathiser who would later defect to Mao's side during the Civil War and serve in his government.
According to Chang and Halliday, Zhang deliberately escalated the situation by orchestrating the Ōyama incident (the killing of two Japanese soldiers in Shanghai) and spreading misinformation to the media about the Japanese attacking the city. This was done in order to pressure Chiang into giving him the greenlight to attack the Japanese garrison there, as Chiang wasn't nearly as gung ho about the whole idea.
The ensuing battle, in which over 700,000 Chinese troops faced off against 300,000 Japanese, saw the decimation of Chiang's army. It resulted in the loss of hundreds of thousands of lives (including Chiang's most elite German-trained troops) and the capture of both Shanghai and eventually Nanking.
What do you think? Is this some crazy crackpot idea invented to demonise Stalin, Mao, and communism as a whole; or might it have some basis in reality?
Absolute bullshit. The Japanese already had colonial holdings in China in 1911 before the USSR even existed. The national struggle against the japanese was already on the rise in Manchuria well before the Marco Polo Bridge incident. The KMT had all but declared war on the Japanese as part of the war for reunification.
Nobody was looking at China in the late 1930s like a eminent threat. Especially not the USSR who were supportive of the Chinese revolution. There was no risk of China going to war with Russia. They were in the middle of reunifying the country after a revolution against imperialism and there were clear signs of the coming civil war between the KMT and CPC.
Jung Chang and Jon Halliday are hacks. Even Kissinger thought they over demonized Mao.
What about German and Japanese efforts to integrate China into the Anti-Comintern Pact? Don't you think the Soviets were worried about that?
The Soviets were Historical Materialists. Why would they be worried that China's nationalists party and communist party would side with the nation colonizing them? There was never any chance that China would alienate Russians (Who had been a historical rival of japan) in order to make Japan and germany feel more comfortable.
Only the idealistic hubris of a fascist could come up with plan to try and convince a nation to side with the people genociding them against the genocider's biggest and closest rival.
Even if the Soviets and CPC didn't exist Chinese nationalists would have demanded the japanese leave China. The only way the Chinese would have sided against the USSR is if they were willing to be subjugated by Japan. The KMT were primarily an anti-colonialists movement (until the civil war) so they were never going to agree to anything less than the expulsion of all foreign powers. Imperial japan was economically and industrially dependant on the colonial exploitation of Manchuria. There's no room for compromise there.
The only way any of this makes sense is if you completely discount China's will for self determination. You would have to believe that Chinese people are genetically predisposed to wanting a boot on their neck.