Lengthy interview on the subject with an Orthodox Metropolitan

So, in your opinion what is a realistic common ground for common answers to such open questions?
     ZIZIOULAS: For the future development of dialogue on this issue, it is of crucial importance that the Orthodox accept that primacy is part of the essence of the Church and not a matter of organization. They must also accept that there must be a Primacy on a universal level. This is difficult at the moment, but it would become easier if we thought more deeply about the nature of the Church. The Church cannot be local without being universal and cannot be universal if is not local.

     And on Catholic side, what can help the dialogue?
     ZIZIOULAS: Catholics must take seriously the notion of full catholicity of the local Church promoted at Vatican Council II, and must apply it to their ecclesiology. This means that every form of primacy at the universal level must reflect the local Church and must not intervene in the local Church without her consent. Every local Church, must have the possibility to affirm its own catholicity, in relation to the primacy. For this reason, I repeat, the golden rule for a correct exercise of primacy is the 34th Apostolic Canon.

From 30 Days – good articles about many other aspects of the Global Church.