The First World War was the first ‘modern war’ – not only on the level of matériel (notably the new aeroplanes, tanks and U-boats) but also of personnel, because of the involvement of the whole of society. War began to acquire totalitarian traits.
The war demonstrated the susceptibility of modern mass societies to nationalistic chauvinism and the glorification of force. The war rhetoric fell on receptive ears and at the beginning of the war the dominant mood was one of euphoria.