There have been four long years of war. Almost a quarter of a million people dead. Millions more displaced.

More rebel groups and ISIL fighters are infiltrating and taking territory.

The future of Syria's president, Bashar al-Assad, is increasingly in question.

Assad welcomed Iran's foreign minister on Wednesday. After signing a landmark nuclear deal with world powers, what is Javad Zarif doing in Damascus?

The visit by the major ally of the Syrian leadership follows increased diplomatic efforts; Russia, the United States and several Middle Eastern powers are all trying to find a way to end Syria's conflict.

Presenter: Shiulie Ghosh

Guests:

Radwan Ziadeh: Executive Director, Syrian Center for Political and Strategic Studies.

Arron Reza Merat: Iran analyst for the Economist Intelligence Unit.

Christopher Swift, from the Center for National Security Law at the University of Virginia.

Source: Al Jazeera