The study is based on hitherto unpublisched Czech and German sources, Austrian and German published materials and selected memoirs. The German´s target of the project of the Customs Union with Austria was to gain Mitteleuropa under their political and economical supremacy as well as to solute economical problems of both countries should have been presented at session of the Study Commission of European Union as a new organization of economy realized by regional agreements according to „Briand Panevropa“.
The common plan was rejected by France und Czechoslovakia. In May 1931 the argumentation of Julius Curtius and Johannes Schober was rejected by other statesmen.
The persisting economical troubles of both German speaking countries and the constant French opposition led to the split of the Customs Union.