Germany was restricted by the Treaty of Versailles after World War I, and its economic and military cooperation with the Republic of China was mostly mutually beneficial. Germany sold many weapons and equipment to the Republic of China and sent military observers, while the Republic of China sold many strategic materials to Germany. Moreover, the Weimar Republic, which fought military cooperation with the Republic of China, was not Hitler's third Reich, and Sino-German military cooperation was completely interrupted during Hitler's period.