The establishment of diplomatic relations between the Federal Republic and Israel the official date was 12 May 1965, the day the letters were exchanged between Chancellor Erhard and Prime Minister Eshkol and the near-certainty that the outstanding issues between the two countries would be solved, did not at first create complete harmony. The negotiations about West German economic aid to Israel to replace the expiring Luxembourg Restitution Treaty, foreshadowed in Erhard's letter to Eshkol, led to serious differences of principle between the two governments. The Jerusalem government was now at pains to persuade the West Germans that this did not mean that they had been released from their moral debt. The extra-parliamentary opposition (APO) was a spontaneous outbreak of student discontent in 1967 manifesting it in street demonstrations, sit-ins and in some cases riots. The New Left brought about few real changes other than university reforms.