In the aftermath of the Wall Street Crash of 1929 and the subsequent worldwide economic crisis, the Empire of Japan pursued an expansionist policy against its weakened neighbors in the Far East. On 18 September 1931, Japan staged the Mukden Incident using it as a pretext for its invasion of Chinese Manchuria. Japan went on to transform the north–east of China into a puppet state under the name of Manchukuo. In the plans of the Japanese general staff, Manchukuo was to serve as a stepping stone for the future conquest of the rest of China. Facing increasing pressure China strengthened its ties with Germany. Starting from 1933, a German mission headed by Hans von Seeckt provided crucial military support to the government of Chiang Kai-shek, reorganizing the army and providing training and modern arms. German aid began to wane in 1937 and was cut completely in May 1938, as Adolf Hitler realigned himself with Japan and Manchukuo instead.