Wang returned to Shanghai in June, 1911, and took another position with the YMCA before being recruited to join the new Republican government in Beijing, then in
Sun Yat-sen's opposition government in Canton. He represented the interim Canton government in China's delegation, headed by
Lu Zhengxiang, at the
Paris Peace Conference, 1919 after
World War I. He and
Wellington Koo, another US-educated lawyer, played prominent roles in presenting the case for returning
Shandong to China and in the decision not to sign the
Treaty of Versailles because it stipulated the transfer of German rights in Shandong to Japan. Notwithstanding their competitive positions domestically, Wang and Koo joined forces in staunchly promoting the formation of the
League of Nations, jointly authoring a pamphlet on the subject. Wang served as foreign minister, minister of finance, minister of justice and acting premier for various short periods of time from 1924–1928, before serving as foreign minister until 1931. He also founded a Shanghai brokerage house; was chairman or board member of mining, cotton milling, and railroad companies; and was Chairman of the Far Eastern Olympics. As foreign minister, Wang negotiated a settlement with Japan over the
Jinan Incident of 1928; with Soviet Russia over the
Chinese Eastern Railway in Manchuria; treaties restoring Chinese territory in British Weihaiwei and French Tonkin; and tariff autonomy or commercial agreements with more than a dozen countries, including Japan. ==Sports==