The Chinese Communist Party is nothing if not expert at the use of the psychological sleight of hand in times of ideological crisis.
They were at their most belligerent in the 50s and 60s when they had a barefoot army with no force projection ability whatsoever. Now, they cry openly about their victimhood while they work around the clock to increase their supply of ballistic missiles and establish a blue water navy.
The idea is to distract the world's attention by inviting discussions on events that took place a lifetime ago. As soon as the Chinese relinquish their control of Tibet (where the actions of their soldiers were not appreciably more honorable than the Japanese in Nanjing, according to Tibetan sources) and apologize profusely for their unjust occupation of Eastern Turkestan and Southern Mongolia, then I will stand with them in their quest to acquire a sincere apology for the Japanese.
Therein lays the problem. There is no denying what the Japanese did was horrible. But Mao's Communists would go on to outdo the atrocities at Nanking en masse on a scale unimaginable. Chiang Kai-Shek's Nationalists, had they been able to maintain mainland China to this day, would've been the only political entity that could've, without incredulous hypocrisy, demand an accounting from the Japanese.
No force projection ability whatsoever? I seem to recall them projecting rather well against your army at Chosin Reservoir. What ever happened to Task Force Faith?