Greek Constantinople, Greco Straits

After World War I, Greece annexed all European territory of the Ottoman Empire plus the Turkish Straits.
Its called Greater Greece (Megali Idea)

Here is what it would look like.

8503174521_b6574b89bb_k.jpg
 
Thing is, the Treaty of Sevres did not include a clause giving Constantinople to Greece. The border, as shown on the map kindly provided by @lordroel, was somewhat to the west of the City, which was to by occupied and administered by an international force for an indeterminate length of time.

A possible POD to gain those border in Thrace could be a decision not to grant Greece a mandate in Smyrna. It was that which really kicked off the Turks in opposition to the treaty. Better to either create a smaller 'free city' of sorts with just the metropolitan area, minus most of the hinterland. Perhaps integrate it economically with Greece, a la Danzig-Poland. Just don't transfer sovereignty to the Turks' hereditary enemy.

If you do this, the Turks are less likely to oppose the new border in Thrace. Furthermore, they will have virtually no means of retaking the territory. The Greeks lost the Greco-Turkish War because they committed too much to Anatolia, exhausting themselves and losing diplomatic support. If they settle for the 'free city' idea, they can consolidate their Thracian territories.

Then, later, it might be possible to have Greece annex Constantinople in a similar way to how Italy annexed Albania IOTL. If the British and French withdraw, or if Turkey looks like its making moves to retake their old capital, the Greeks may act to prevent such an outcome. Again, there would be little the Turks could do to prevent such an action - Greece is more than capable of maintaining naval dominance in the Sea of Marmara to prevent Turkish landings.
 
Top