Through Kokoschka he came into contact with Herwarth Walden and got it published in Der Sturm, and later in Franz Pfemfert's magazine Die Aktion.
Ehrenstein quickly became one of the most important voices of expressionism and came into close contact with Else Lasker-Schüler, Gottfried Benn and Franz Werfel.
It was widely circulated Anton Kuh Spottvers wrote about it: "its a high honor of a work, only its verses disturb you.
From 1916 to 1917 he belonged to the circle of the first Dadaist magazine The New Youth, in which he published work alongside Franz Jung, George Grosz and Johannes R. Becher.
After 1918 he supported the revolution in Germany and signed, along with several others including Franz Pfemfert and Zuckmayer, the manifesto of the Antinational Socialist Party.
Hermann Hesse tried to help him to get permanent asylum for Ehrenstein but only managed to get him temporary Residence Papers.
He went to England to his brother Carl, then to France, until he was finally able to leave the country for Spain and then to the United States in 1941.
In New York he met other exiles, including Thomas Mann, Richard Huelsenbeck, and George Grosz, and was granted a residence permit.
Ehrenstein learned English, but found no work and lived on the income of articles he wrote for the newspaper, and by loans from George Grosz.