In the mid-1930s he was the target of Japanese attempts to get him to incorporate his province of Shandong into one of the North China puppet states they were attempting to construct. After the onset of the Second Sino-Japanese War, he commanded the 3rd Army Group and in 1937 was made Deputy Commander in Chief of the 5th War Area defending the lower Yellow River valley. Han was suspected of having conducted secret negotiations with the Japanese to spare his province and his position of power. When the Japanese crossed the Yellow River he abandoned his base in Jinan. Han abandoned his army on January 6 and fled to Kaifeng, where he was arrested on 11th and brought to Wuchang and was later executed by Chiang Kai-shek for disobeying orders from superior commanders and retreating on his own accord.