Treaty of Paris (1815) notably Prussia, initially demanded that France cede significant territory in the East, rivalry among the powers and the general desire to secure the Bourbon restoration made the peace settlement less onerous than it might have been. The treaty was signed for Great Britain by Lord Castlereagh and the Duke of Wellington and by the duc de Richelieu for France; parallel treaties with France were signed by Austria, Russia, and Prussia, forming in effect the first confederation of Europe. The Quadruple Alliance was reinstated in a separate treaty also signed 20 November 1815, introducing a new concept in European diplomacy, the
Nine-Power Treaty shown to be completely ineffective. During the Washington Naval Conference of 1921–1922, the United States government again raised the Open Door Policy as an international issue, and had all of the attendees (United States, Republic of China, Imperial Japan, France, Great Britain, Italy, Belgium, Netherlands, and Portugal) sign the Nine-Power Treaty which intended to make the Open Door Policy international law. The Nine-Power Treaty, concurrent with the Shangtung Treaty of the Washington Naval Conference, effectively prompted Japan to return territorial control of Shandong province, of the Shandong Problem, to the Republic of China. The Nine-Power Treaty was one of several