The essence of the “border problem” between Poland and the FRG reaches back to the provisions of the Potsdam Agreement of 1945. The Polish position was unambiguous from the beginning: the border on the Odra and Nysa Łużycka rivers was established under international law in the Potsdam Agreement, while the subsequent actions undertaken within the framework of the “peace settlement” could only have complementary, declaratory significance. On the other hand, in the FRG an official legal position was developed according to which the former eastern German territories were only given to Poland (and the USSR) “under their administration”, and the final decision on the border was left to be taken by the future unified Germany in a “peace treaty” or a “peace settlement”. This position was not changed by the Normalization Treaty between Poland and the FRG of 1970, because it was interpreted in the FRG as only a “treaty about the renunciation of force”, an element of a modus vivendi which was to last until the unification of Germany. On the other hand, the Zgorzelec Treaty of 1950 between Poland and the GDR was interpreted as not binding for the future unified Germany. Such a position deeply destabilized political relations between the FRG and Poland in the post-war period and had a conflict-generating significance in a number of areas. At the beginning of 1990 the political changes in Poland coincided with the process of German unification. The democratic opposition in Poland, and thereafter the government of Tadeusz Mazowiecki, unequivocally supported the right of the German people to self-determination, at the same time expecting an unequivocal position on the Polish-German border. This fundamental problem was closed in 1990 under two international agreements: the Treaty on the Final Settlement with Respect to Germany (2+4 Treaty) and the Treaty between the Federal Republic of Germany (united Germany) and the Republic of Poland on the confirmation of the border between them. Thus for thirty-plus years now the “border problem” has been removed from the agenda of political discussions in Polish-German relations, which proves the effectiveness and durability of the agreement reached, which was reflected in both treaties.

This contribution discusses the unresolved claims of Poland and Germany arising from the destruction, removal, and appropriation of cultural property during and immediately following the Second World War; viewed against the background of the 50th anniversary of the 1970 Warsaw Treaty and the 30th anniversary of the 1990 2+4 Treaty. It provides an analysis of the extent to which these and other bilateral treaties between Germany and Poland impose legal obligations to restore or compensate for the destruction or loss of cultural property. Finally, it suggests pragmatic solutions to overcome the convoluted political, diplomatic and legal debates in the spirit of “cultural internationalism” and in line with the proposals of the Copernicus Group of Polish and German historians.

The Western boundary of Poland was established by the Potsdam Agreement of 1945 and confirmed by the Boundary Agreement between Poland and the GDR of Gőrlitz of 1950. Poland exercised administration with respect to the adjudicated territories, but she made efforts to get the boundary recognized and confirmed by the FRG. This happened on the basis of the Warsaw Treaty of 1970. Boundary treaties are usually considered as objective regimes. It is disputable whether the Warsaw Treaty of 1970 can be classified as such a regime.