After the dissolution of the OSS in 1945, Marcuse was employed by the US Department of State as head of the Central European section, retiring after the death of his first wife in 1951.
Setelah pembubaran OSS pada 1945, Marcuse dipekerjakan oleh Departemen Dalam Negeri Amerika Serikat sebagai kepala seksi Eropa Tengah, dan pensiun setelah kematian istri pertamanya di 1951.