During the Nanjing Decade the nationalist leader of the Chinese Government was experiencing a threat from two different sides. It was the time of Japanese aggression, so Japanese military forces were on their way to invade Chinese territory. At the same time, inside of the country the Government was facing a threat from the Communist protesters.
Chiang Kai Shek, the leader of the Nationalist Government of China found his country drowning in the boiling conflicts and had to decide which of the two big threats to fight first. He called these threats “the disease of the heart” and “the disease of the skin”.
Japanese invaders were labeled as “the disease of the skin” because of several reasons. First of all, skin diseases are happening outside, on the surface of the skin, just like Japanese invasion that was coming from the outside. Besides, the Japanese were ideologically convinced that they were a better nation than the Chinese, they believed that being born Japanese (in Japanese skin) gave them rights to kill and torture Chinese people.
Communists were labeled as the “heart disease” because they were coming from the inside, from the heart of the country and were trying to destroy it, and destroy the Chinese soul with their official atheism propaganda.
Chiang Kai Shek logically decided that inner threat was more dangerous for the country, and started multiple annihilation campaigns against the Communists. However, when in 1937 the Japanese invasion started, and the outer threat became very serious, the two fighting parties of China united; Chiang Kai Shek signed a temporary peace agreement with the communists to protect his country from the mutual enemy.