Answer:
Anti-Japanese sentiment.
Explanation:
The Second United Front (traditional Chinese: 第二次國共合作; simplified Chinese: 第二次国共合作; pinyin: dì èr cì guógòng hézuò; lit. 'Second Nationalist-Communist Cooperation') was the alliance between the ruling Kuomintang (KMT) and the Chinese Communist Party (CCP) to resist the Japanese invasion of China during the Second Sino-Japanese War, which suspended the Chinese Civil War from 1937 to 1945.
