Many (though it's an increasingly shrinking number nowdays) Orthodox Hierarchs really do believe in the whole "ecumenical dialogue", and that it will possibly result in the legitimate reconciliation of heterodox groups to Orthodoxy.  As such they feel they don't want to do anything to upset this.  Personally, I think this is misguided; not because I believe there's anything essentially wrong with talking to the heterodox in a civil manner and taking a go at "honey over vinegar".  Rather, I believe this is so because I don't think the process itself is working, and has in fact round aboutly done more harm to the Church Herself than helped anyone outside of Her "come around" to a better way of thinking.  The whole thing has very often been simply a temptation to sin, and sometimes very scandalous sins at that (this is the harm to the Church I'm speaking of, as well as the obvious direct harm done to those who participate in the excesses of the "ecumenical movement").
Very well-said Augustine. I have only a small "objection" (which is not really an objection

): I don't think at all that there is even one hierarch or priest among them who are too much fan of the so-called "ecumenical dialogues" that truly believes that he does so because it could result in the "legitimate reconciliation groups to Orthodoxy". The ecumenists are not that naive! It'just a pretext rehashed like a chewing-gum. I don't know any convert among the heterodox participating in these "dialogues" (imagine, f.ex., a protestant theologian who after a session would declare "I was convinced by the arguments of the Orthodox side and I want to be received into the Orthodox Church!

Pure science fiction!). Well, I think the "dialogues" have become a - well-financed - entreprise and almost a cult object, an "article of faith" for some secularized clergymen and theologians, who are not really interested in confessing Orthodoxy by deeds and words... Metropolitan Damaskinos of Switzerland (EP, he has abdicated) had participated even in interreligious "shows" (unfortunately, he wasn't alone!). I don't think that Metr. Damaskinos managed to attract any heterodox to the Orthodox Church by his "ecumenical" (or "ecu-maniac") activities. On the contrary, I do know he scandalized quite a few people. On the other hand, quite a few heterodox have become Orthodox by visiting Mt Athos, other monasteries in Greece, in France, in England (especially the monastery of St John the Baptist, founded by blessed Elder Sophrony) or monasteries in the USA. It is well-known that no representatives of the monastacism participate in the so-called "dialogues" (thanks God!).
Of course, I am not for a zealotic attitude towards the heterodox Chrisians and I don't mean that an Orthodox should avoid any contact or dialogue with non-Orthodox or even non-Christian people (I have very good friends that don't share my faith, even a good French friend who has not been baptized at all). I would like just to stress that the institutionized "ecumenical dialogues" have become a source of troubles for the Orthodox Church, mainly because of the secularism of the Orthodox participants in them. To say it straight out, most of the Orthodox faithful today who are conscious about their faith, at least in the tradionally Orthodox countries, don't believe that the bishops or priests who participate systematically in such dialogues are able to witness the Faith. In fact, some of them are so willing to confess the Orthodox faith to the heterodox that they are ashamed (or just don't want to) of observing a fast in a common meal

!