How does the killing of an innocent child ever become moral?
Not liking the answer does not make it any less answered.
A little more light bedtime reading for you.
In 1942 Ishii (the head of Unit 731) begins field tests of germ warfare on Chinese soldiers and civilians. Tens of thousands die of bubonic plague, cholera, anthrax and other diseases. U.S. soldiers captured in Philippines are sent to Manchuria.
During the six weeks of the Nanking Massacre, the Chinese were not simply murdered. They were tortured, humiliated, and raped. The Japanese used a wide variety of methods of murder. They chased the Chinese into the Yangtze River with machine guns, drowning them. They poured gasoline on people, and shot them, so the victims flickered up like candles. They cut the eyeballs out of men, and then burned the people while they were still living. They tied Chinese civilians up on posts, and threw grenades to watch their flesh fly. A Japanese general poured acid on a man until he died of corrosion. Some Chinese were attacked with awls. Others were castrated. Some Chinese even had their hearts cut out. Some women were beaten at the vagina with fists and other objects until they died. Even babies were victims; they were skewered and tossed into boiling water. Hakudo Nagatomi, a Japanese war veteran, described, "I remember smiling proudly as I took his [another general's] sword and began killing people...The head was cut clean off and tumbled away on the ground as the body slumped forward, blood spurting in two great gushing fountains from the neck."
The Japanese finally left China when the United States dropped the atomic bombs on Hiroshima and Nagasaki.