Everyone knows that Turks are just Muslim Greeks. They have kebabs, barbers and an unhealthy preoccupation with Cyprus, therefore, Greek. Logic, innit?
Snark aside, this is basically true. Until very recently "Greek" and "Turk" weren't ethnic or linguistic identities but religious identities. In the 1923 Swap, Karamanli Christians who spoke nothing but Turkish were sent to Greece, and Cretan Muslims who spoke nothing but Greek were sent to Turkey. The two populations, Greek and Turkish, are essentially descended from the same population that inhabited the area in millenia past. The Turkish migration into Anatolia was a migration of language, religion, and culture as much if not more than physical migration of people, especially for Western Anatolia.
My dear fellow, your suggestion was that Vietnam wasn't "an issue" prior to the Kennedy administration. The war started with US military advisors, because it was wrongfully assumed that South Vietnam would be able to put up some defense of its own. Those "advisors" became involved in actual fighting rather soon, when it became that advisors and materiel wouldn't hold up the South Vietnam "domino", which was considered essential in the then predominant containment policy. The US escalation in Vietnam resulted ultimately not only in Vietnam falling, but Laos and Cambodja as well. The fact that Kennedy started the escalation on a major level suggests that Johnson could make a "radical change", as you said. He failed.
This post is about as clear as Bangkok canal water. I really don't know what you are trying to say here. That the Vietnam War was an issue prior to Kennedy, but after Kennedy it became an issue? And how does Johnson's failure or otherwise even related to this.