Elder Paisios from the Holy Mt. Athos. He was also a excellent scripture interpreter and predicts one day that Constantinople will again be Greek.
The wheels of history are always turning. If it happens in any distant future that Turkey is weaker than Greece in economy and defense and the world geopolitics is such that the other countries couldn't care less, Greece would invade Turkey.
The Turks would destroy them. The modern Hellenic State has no go power economically and is disfunctional politically. The Turks outnumber them. More Turks live in the environs of Istanbul that in all of Greece. The Turkish Army is larger, better trained and equipped and has more operational experience. Shall I add that the Turkish economy and governmental institutions are much stronger too? I have travelled extensively in both countries. You can always hear the Greeks bad mouthing the Turks, but rarely do hear the turks bad mouthing Greeks. I once pointed this out to a Turkish gentlemen and he said, "we like Greek people, we eat the same things, we listen to the same music and we like to drink the same alcohol. We even have the same faces! Look Turkey is bordered eight countries, including Syria, Iraq and Iran, you really think we worry about Greece?" He also pointed out that both Greece and Turkey are members of NATO.
That said, Constantinople was Greek, at least demographically until post the WWI "population exchanges" traded balkan Muslims for Orthodox Christians. This was the major result of the Greek Kingdom's disasterous decision to fight Britian's proxy war against Kemal Ataturk's nascent Turkish Republic. They were soundly defeated, and utterly humiliated by Ataturk's army.
The modern Greek state, like most Balkan Counties, owes its existence more to the intervention of the "Great Powers" into Osmanli affairs, than to their own efforts. Britian, France and Russia created the Hellenic Kingdom as a rump state and placed an European Princeling on its throne. Its expansion in the early twentieth century was made possible by the effectiveness of the Serbian and Bulgarian Armies in engaging and defeating the main Ottoman armies in Thrace and Macedonia which left the area around Thessaloniki mostly undefended during the First Balkan War. Further expansion of the Kingdom was through adjustments made by the Victorious Powers after WWI (Bulgarian Aegean Thrace) and and WWII (the Italian Dodecanese), rather than military actions by the Greek Army itself. This is not to say that Greeks didn't show great heroism in fighting against the Turks in Europe and Asia Minor, or against the Italians at the beginning of WWII* or the German occupation later in that war.
The Greek Army's junta also initiated a disasterous coup against the government of Archibishop Markarios in a foolhardy attempt to annex Cyprus This resulted in the invasion of the Turkish Army and the division that lasts until today.
No. The only way our Greek brothers are ever going to get back Istanbul, is if somebody else gives it to them.
* A truly brilliant victory over Fascist Italy in the mountains of Albania.