We need a definition of terms here. For me, dialog with any and every one is good, provided it conforms to:
Mark 16:14-16
King James Version
14 Afterward he appeared unto the eleven as they sat at meat, and upbraided them with their unbelief and hardness of heart, because they believed not them which had seen him after he was risen.
15 And he said unto them, Go ye into all the world, and preach the gospel to every creature.
16 He that believeth and is baptized shall be saved; but he that believeth not shall be damned.
I believe you are referring to evangelism as dialog. You can evangelize individuals and only individuals because accepting Christ is an individual choice.
When you say you are going to dialog with the Islamic world you are referring to a couple billion people and what you are really referring to is speaking with the leadership of the Muslim community. I very much doubt that the leadership of the Muslim world is going to cozy up to the Catholic Church unless it is a strategy to destroy the Church. Not to mention that past leaders who made peace with west have risked assassination.