西安事件
On 12 December 1936, the disgruntled Zhang and Yang conspired to kidnap Chiang and force him into a truce with the CCP. The incident became known as the Xi'an Incident. Both parties suspended fighting to form a Second United Front to focus their energies and fight the Japanese. In 1937 Japan launched its full-scale invasion of China and its well-equipped troops overran KMT defenders in northern and coastal China.