The problem with Aya Sofya is that it represents sovereignty in the Aegean and Black Sea. When Sultan Mehmet conquered Constantinople, Aya Sofya, as the the crown of Caesar, passed to him, and Orthodoxy was subdued before Islam.

When Aya Sofya became a museum, it represented the subjugation of Islam at the same level as the other Christianities before the new secular world order of the 20th century.

It also suspended Caesar's crown; the Turk would no longer be a Sovereign in his own land, owing "obligations" under "international treaties" to historic foes like Russia. But the Russians would not get this crown (nor the straits) either.

The fear is that, should Turkey make Aya Sofya a mosque again, it would signify Turkey's Sovereign Will is reborn and once again declare the inferiority of the Greeks, Russians and their Balkan satellites (Serbia etc) before the inheritors of Caesar's crown.

The secular order would be rebuffed. The post-war fiction of legal equality between states would be thrown into the dustbin of history.

And one begins to hear something, somewhere far off into the distance...

Drums, drums on the horizon.