Part of his duties in the Interior Ministry involved providing a legal framework justifying the Nazi expansionist policy under constitutional and international law. On 16 March 1938, Hitler charged Stuckart with the management of the office carrying out the unification of Austria with the Reich, and he drafted the implementing decree. He was formally promoted to State Secretary in the Interior Ministry on 1 April 1938. In October he was similarly charged with administering the transfer of the Sudetenland and in March 1939 drafted the decree on the formation of the Protectorate of Bohemia and Moravia.