 At the beginning of the First World War, Ehrenstein, who was deemed not fit for military service, was ordered to work in the Vienna War Archives.While many other artists were initially carried away by enthusiasm for the war, Ehrenstein from the beginning was a staunch opponent of the war, which he articulated clearly in a series of articles and poems ("The man screams").During the war he came in contact with Walter Hasenclever and Martin Buber.