Hundreds of countries in the world have EEZs [0], but let's make it a big deal for Greece even though it currently doesn't actually exercise their rightful claim to have one. The stability of the region would not be destroyed by Greece utilizing their EEZ, but from aggressive unstabilizing countries claiming borders they don't have and having military presence in places where they shouldn't be.

[0] https://en.wikipedia.org/wiki/Exclusive_economic_zone