Greece has a population of 10 million, Turkey 86 million, but things are even worse than they seem because the Greek population is old, the ratio of Turkish to Greek military aged men is over 12 to 1. Greece's economic development has been stifled by the EU, while Turkey's more unconstricted. Turkey has a thriving MIC with their own 5th generation fighter program and an advanced drone warfare industry.
Thinking about it, it is pretty likely that Turkey might make a move on Cyprus, or some of the Greek islands adjacent to Asia minor. Cyprus maybe less so as it is a de facto British/NATO/EU strategic colony, but in a multipolar world, Turkey is likely to flex and ascend to regional power status as its demography and modern military makes it a local heavyweight.
Turkey's population is not homogenous at all, it consists of numerous different ethnicities (including secret Christians, and a large percentage of descedands of muslimified Greeks/Romans, Kurds, Laz etc. In the unlikely total war scenario that you imagine, they can count on 2/3 of that 86 million, if that. The average Mongoloid soldier is a coward at heart and has a deep-seated inferiority complex against the Greeks, thanks to centuries of living in a demonstrably foreign land surrounded by ancient Greek ruins and having to name literally all their towns, cities, mountains, rivers, food recipies, musical organs etc with Greek sounding names.
Their high command is haughty, lacking in deep strategic thought and potentially mutinous, with a Kemalian/secular outlook still remaining in the background. After the 2016 failed coup, their armed forces are apparently loyal to Erdogan, but that's only a personal loyalty driven by fear, which will disappear when Erdogan dies.
Their foreign policy is irrational and based on unwarranted pride. It has made them an untrustworthy ally. They have lost America's trust and haven't trully gained Russia as an ally. They bought the S-400 system from them which still is not operational, 8 years after the purchase, and it will never be allowed to become operational.
They have nothing that they can trully call their own (except perhaps the Turkish toilet, which is a hole in the ground). The land itself wants them out, they have never managed to truly make it their own. Unless they become Christian, they will forever live in a state of perpetual cognitive dissonance.
Their so-called MIC is a joke, a conglomeration of copied, poorly made and low-performing material. Would you buy a Turkish car if they made one?
Their economy is concentrated around Constantinople and the Aegean coastline ($16,000 per capita). Their eastern provinces are impoverished and decades behind the rest of "their" country ($4,000 per capita).
A short war is much more likely, which nullifies the alleged demographic and economic advantage. It will be fought by the two opposing standing armies, not by drafted infantry armies. Let's get more into that:
Turkey's borders are 1700 miles in total. That's only a little less than Germany's eastern front in October 1941. That must give you a sense of how strategically stretched the Turkish military must be to monitor and defend such a long border. They have 5 fronts to cover: eastern (Iran, Iraq, Armenia, Azerbaijan, Georgia), southern (Iraq, Syria), eastern Mediterranean (Cyprus, France), Aegean and lastly the Evros land border with Greece, which is only 130 miles long.
That's a modern Maginot line behind a river. I have served there in an armored brigade and I can tell you, if the Turkish army attacks it will get mauled. The Aegean front? How will they invade without air and naval superiority (yes, they don't have those). Their navy lacks tradition and seamanship, and their pilots are inferior to the Greek pilots (especially after the 2016 airforce purge). Even if they manage to land to a nearby island (unlikely), how will they maintain the SLOC against the German made Type 214 subs inside an air space dominated by the Greek airforce? The Greek airspace is impregnable. On the other hand, Turkish air defense is like Swiss cheese, which means their feable MIC will be in flames within days of a conflict breaking out.
Cyprus is another matter, because Greece has lost the strategic reach to protect Cyprus since the '70s. But that fact has been countered by strengthening alliances with France and America. There are large deposits of natural gas SE of Cyprus and Turkey won't dare to threaten those, as long as other NATO members are involved.
