[Diopos]

It is all about options, and tuning mechanisms.
With Greece and Cyprus in there is a possibility of someone saying no to Turkey without that someone having to be France or Germany and, in denying Turkey, opposing the US. Remember the times back then. Promoting a common currency, without a "unification" of interests either on foreign affairs or defense, the induction of the former Warsaw Pact countries en masse and in a hurried manner, the Turkish issue and so on. Some of the european leaders of the time sought some options as most of the above were initiated or "controlled" by the US. Thats the main role of Greece. An option. Plus a good location on the map of course and not much of a financial burden after all.