This catalog, published on the occasion of the exhibition "To the East, endless war", presented at the Army Museum, explores the aspects and the stakes of the establishment of peace, between 1918 and 1923 , in the states of Eastern Europe. The First World War ended in 1919 with the signing of the Treaty of Versailles. After the armistice of 1918, Eastern Europe is still crossed by multiple violence and knows various military interventions. Thanks to 14 essays written by the leading specialists and to an Atlas of 25 countries to understand the evolution of the borders in the East between 1918 and 1923, this catalog allows to know how peace has been established in this area. space, to discover the prolongation of the French war to the East and to understand how the modification of its borders is still impacting geopolitics even beyond the borders of Europe.