The other nations, including Germany, America and Britain, maintained their own chemical and bio-weapons programs during the war. Mussolini’s Italy even employed mustard gas in Ethiopia in 1935. Yet fear of retaliation deterred the major powers from using chemical or biological weapons against each other. But Imperial Japan had no such fear because backward China had no Weapons of Mass Destruction and no other means of massive retaliation. Moreover, Tokyo viewed the Chinese as a racially inferior enemy—one that foolishly resisted a massive Japanese army that tried for nearly a decade to subdue China.

The Battle of Shanghai was one of the largest and bloodiest battles of the entire Second Sino-Japanese War. The battle lasted for three months and involved nearly one million troops and approximately 300,000 died on both sides. The Japanese anticipated taking Shanghai in an incredibly short time, but the Chinese nationalists, despite inferior equipment and training, managed to delay them there for three months. The Japanese eventually drove the Chinese out, but were shocked at the intensity of the Chinese fighting and the scale of their own losses. The Japanese victory was in part as a result of naval artillery fire and aerial bombing. The army marched into the city, seizing assets and carting away anything of value. They conducted wide-spread attacks on Chinese civilians when the army entered the city. The stubborn fighting in Shanghai was one reason the Japanese acted so brutally when they took Nanking.