World Disarmament Conference
Shtein was a secretary of the Soviet delegation at the Genoa Conference in 1922 and the secretary-general of the Soviet delegation at the Hague Conference in 1927. Also he was the Secretary-General of the Soviet delegation at the International Economic Conference in Geneva between 1928 and 1933. He was the secretary-general of the Soviet delegation to the Preparatory Commission in the World Disarmament Conference.