By challenging prevalent ‘realist’ interpretations, this article seeks to open up a new perspective on Anglo-US efforts to create a viable Euro-Atlantic peace system after 1918. Its main thesis is that significant advances to this end did not result from enforcing the Versailles system but rather from a qualitatively new process of peaceful change: the making of the ‘unfinished transatlantic peace order’ of the 1920s. Initiated by Anglo-US policy makers, this process led to the first ‘real’ peace settlements after 1918, the London reparations settlement of 1924 and the Locarno pact of 1925. Crucially, these settlements fostered Germany's international reintegration on terms acceptable for France. They thus prefigured the terms on which more permanent stability was achieved after 1945.