The Second United Front was the alliance between the Kuomintang and Communist Party of China during the Second Sino-Japanese War that suspended the Chinese Civil War from 1937 to 1940. During the Japanese invasion and occupation of Manchuria, Chiang Kai-shek, who saw the Communists as a greater threat, refused to ally with the Communists to fight against the Japanese. On December 12, 1936, Kuomintang Generals Zhang Xueliang and Yang Hucheng kidnapped Chiang and forced him to a truce with the Communists. The incident became known as the Xi'an Incident. Both parties agreed to suspend fighting and form a Second United Front to focus their energies and fighting against the Japanese.