Rat der Volksbeauftragten
On 11 November 1918, Koeth left active service with the rank of "Oberst" (colonel). Both industrialist and trade union organisations had already lobbied chancellor Max von Baden to put him in charge of demobilisation. Under the Council of the People's Deputies, Koeth became "Staatssekretär" (de facto minister) of the "" (office for demobilisation), a position created for him. When the cabinet of Philipp Scheidemann took office in February 1919, he became "Reichsminister für wirtschaftliche Demobilmachung" (Minister for Demobilisation) until the Ministry was dissolved on 30 April 1919.