Five months after his return from Britain, Reuter was requested to hand in his resignation from the Navy. The Treaty of Versailles forced Germany to drastically reduce the size of its navy leaving Reuter without a suitable command, given his rank and age. Moving to Potsdam, he eventually became a state councillor. He also wrote a book on the scuttling of the High Fleet, "Scapa Flow: Grave of the German Fleet". On 29 August 1939, he was made full admiral by Hitler to celebrate the 25th anniversary of the Battle of Tannenberg.