Between last Thursday and Monday, the Turkish government, in league with Saudi Arabia, made a tentative decision to enter the war on the ground in Syria - and then got cold feet about it. Or more likely, the Turkish army simply told the government that it would not invade Syria and risk the possibility of a shooting war with the Russians.
The Turkish government bears a large share of the responsibility for the devastating Syrian civil war. From the start, Turkey's leader Recep Tayyip Erdogan was publicly committed to overthrowing the Syrian regime of Bashar al-Assad. For five years he kept Turkey's border with Syria open so that arms, money and volunteers could flow across to feed the rebellion.
Erdogan's hatred of Assad is rooted in the fact that he is a militant Sunni Muslim while Assad leads a regime dominated by Shia Muslims. Both men rule countries that are officially secular, but Erdogan's long-term goal is to impose Islamic religious rule on Turkey. Assad is defending the multi-ethnic, multi-faith traditional character of Syrian society - while also running a brutally repressive regime. Neither man gives a fig for democracy.
Saudi Arabia has been Erdogan's main ally in the task of turning Syria into a Sunni-ruled Islamic state (although 30 per cent of Syrians are not Sunni Muslims). Together these countries and some smaller Gulf states subverted the original non-violent movement in Syria that was demanding a secular democracy, and then armed and supplied the Sunni-dominated armed rebellion that replaced it.
The US government also wanted to see Assad's regime destroyed (for strategic reasons, not religious ones). So for years Washington turned a blind eye to the fact that its allies, Turkey and Saudi Arabia, were actually supporting the extremists of Islamic State (Isis) and the Nusra Front, al-Qaeda's franchise in Syria.