Aside from the establishment of the League of Nations and the establishment of a lasting peace, Wilson's other main goal at the Paris Peace Conference was to use self-determination as the primary basis of international borders. However, in pursuit of his League of Nations, Wilson conceded several points to the other powers present at the conference. Germany was required to pay war reparations and subjected to military occupation in the Rhineland. Additionally, a clause in the treaty specifically named Germany as responsible for the war. Wilson agreed to the creation of mandates in former German and Ottoman territories, allowing the European powers and Japan to establish de facto colonies in the Middle East, Africa, and Asia. The Japanese acquisition of German interests in the Shandong Peninsula of China proved especially unpopular, as it undercut Wilson's promise of self-government. However, several new states were created in Central Europe and the Balkans, including Poland, Yugoslavia, and Czechoslovakia. The conference finished negotiations in May 1919, at which point German leaders viewed the treaty for the first time. Some German leaders favored repudiating the treaty, but Germany signed the treaty on June 28, 1919. For his peace-making efforts, Wilson was awarded the 1919 Nobel Peace Prize.