According to the Guardian newspaper, the Tuesday ceasefire in Aleppo was brokered between Turkey and Russia:
“with little input from Iran or the Syrian leadership, who had controlled the battle since Russia scaled back its bombardment.”
According to the same report, this startled the Iranian – Syrian regime forces, as the deal would have allowed some of the members of the opposition to leave the city. As a result on Wednesday, despite the ceasefire, they restarted their attacks. Then they placed new condition for the ceasefire.
And here is where the divergence emerges:
Iran and the Syrian government do not want to compromise on the battlefield or at the negotiating table, believing that total domination will give them a better hand to shape the aftermath. Russia, on the other hand, sees a benefit in transitioning from bludgeoning superpower to peace-broker.
The position of the Iranian and Syrian regimes will be discussed by the EU on Thursday.
The EU, increasingly marginal to a crisis being resolved by Russia, Iran and Turkey , is certain to make it clear that it will not supply any cash for economic reconstruction unless there is a negotiated political settlement – and not a military resolution imposed by Iran or the Syrian government. (I emboldened to emphasize importance).
You can read the rest of the report here