This would be the third massacre of Nanking. The first was in the 15th century, under Ming Emperor Yung Lo, and the second was in the 19th century under Ching Emperor Tung Chih. The ancient Chinese custom of the post-surrender massacre was bloody, but it was effective in ensuring the peace for decades (at the very least) by eliminating the most able potential opponents of the victorious power.

Massacre following siege was the norm. It is not exclusive to Nanking and it is not exclusive to the Chinese and Japanese. Everybody did it.. Even Americans did it.

 

Bear River Massacre 

 

Bloody Kansas 

 

Indian Massacre, and "Spare the women and the children, but kill every man and boy who can shoot!" are well known in this American history.

 

Herald

   

 

 

 

 

In China and Japan, it was a matter of carefully-reasoned state policy, borne out by the actual (negative) experience of successful rebellions in the aftermath of a lenient policy.* In America, they were the result of undisciplined troops, whose commander was often excoriated by journalists and sometimes demoted or prosecuted in the courts.

 

* An early example is that of King Fuchai of the Wu Kingdom in 5th century BC, who spared King Goujian (and the royal retinue) of the Yue Kingdom. The result? Goujian retook the Yue Kingdom and went on to defeat the Wu Kingdom over a decade later.

Normally, Japanese military won't allow this happen. However, the extraordinary bloody Battle of Shanghai-Nanking has loosen up the discipline of Japanese soldiers to the degree that even officers ordered, or even encourage, such behavior of their subordinates.

 

The Second Sino-Japanese War was complete disaster for Japan even before they got into war with the US. Rape of Nankin only made things worse for Japan, due to the anger and rage from Chinese side. Now this is total war. Chinese won't accept peace with Japan unless the single last Japanese soldier in China is either killed or driven away. So, the war dragged on, and neither side can achieve victory.

How about gang rape women then kill them with bayonets? How about killing pregnant women then cut open their belly? Then, how about random killing of civilians regardless of age and gender?

 

 That was not groups of undisciplined brigands led by the traitor, John Brown, and that renegade Quantrill. Those were recruited volunteers under discipline commanded by that bastard, Colonel Chivington. (militia, what would later become the National Guard) 

 

?	I saw the bodies of those lying there cut all to pieces, worse mutilated than any I ever saw before; the women cut all to pieces ... With knives; scalped; their brains knocked out; children two or three months old; all ages lying there, from sucking infants up to warriors ... By whom were they mutilated? By the United States troops ...	?
—- John S. Smith, Congressional Testimony of Mr. John S. Smith, 1865

 

 PBS' The West