In 1917 Siam declared war on Germany and Austria-Hungary, mainly to curry favor with the British and the French. Siam's token participation in World War I secured it a seat at the Versailles Peace Conference, and Foreign Minister Devawongse used this opportunity to argue for the repeal of 19th century treaties and the restoration of full Siamese sovereignty. The United States obliged in 1920, while France and Britain delayed until 1925. This victory gained the king some popularity, but it was soon undercut by discontent over other issues, such as his extravagance, which became more noticeable when a sharp postwar recession hit Siam in 1919. There was also concern that the king had no son, which undermined the stability of the monarchy due to the absence of heirs.