There are two essential questions to understand Syria's future. First, which are the countries that want Bashar Assad to remain in power? The second question, which is connected to the first one, is which countries are willing to maintain Syria's territorial integrity? The position of some countries is quite clear about these two points, whereas there are others whose positions are either changing constantly or remain unclear.
We know, for example, that Iran wants Assad to remain in power and his regime to continue, and this has been obvious since the beginning of the war. As for Russia, even though Moscow wants the Ba'ath regime to continue, they don't insist on keeping Assad in power. They, of course, support Assad now; but their main concern is not Assad's personal destiny, but the future of the Syrian regime. Moscow needs a Syria which would serve as a buffer zone between Israel and Iran; who wouldn't cut ties with Europe, but adopt an anti-American policy; and especially, a Syria who would host Russian military bases. Otherwise, they don't care who the actual president of Syria is.
Russia doesn't want Syria to be governed by Sunni groups, as Moscow believes these are under Saudi Arabia's control, which means they serve indirectly Israel's and the U.S.' interests. That's why Russia supports Shiite groups in Syria, and we must say Russia's position has been constant since the beginning of the war, as well. Putin repeats it clearly on every occasion, as he did recently in the Tehran summit.
As the other important player involved in Syria, Turkey's position is not unknown either. We know that Ankara is against both Assad and his regime. Turkey may accept to put up with Assad until a new constitution is written and free elections are held, but that's about it. In this sense, one may say Turkey's position is quite clear, too.
What Iran, Russia and Turkey agree on, is the need to preserve Syria's territorial integrity. In other words, these three countries don't want Syria to turn into another Iraq or Libya. We know that central governments in Iraq and Libya don't control much, and even though on paper their territorial integrity is intact, we must admit these are actually divided countries.
Russia, Turkey and Iran don't want this scenario to repeat in Syria, and they label as terrorist every armed organization that may have a secessionist agenda. There are many organizations that deserve this qualification in Syria, whether they are affiliated to the Nusra Front or to the PKK. Moreover, these three countries believe the U.S. is supporting these terrorist groups directly or indirectly, and they consider this support as a vital threat to their national security.
The picture becomes blurrier when it comes to European powers. For example, we don't know what France and Germany actually want when it comes to Assad, the Ba'ath regime and Syria's future. It is true they often say Assad is committing crimes against humanity, therefore he should be held accountable. Yet they seem happy about the fact that Assad's military is fighting against radical Sunni groups and leaving the Kurds alone. Besides, they still want to play a role in Syria's reconstruction, especially now when Iran's market seems to be inaccessible again, thanks to U.S. sanctions.Nevertheless, Russia seems to have decided to push the European countries to make clearer decisions. On the one hand, it has decided to hit the Idlib region, and on the other, it incites Assad to fight against the PKK in order to push the latter out of the equation.
As to the U.S., nobody is sure what it wants. For the simple reason that the U.S. has turned into a very unpredictable country. No one expects Washington to start supporting Assad suddenly, but nobody knows what it is prepared to do against Assad, either. Especially when Russia is looking.
While the U.S. is wasting energy with President Trump, Putin is gaining territory, and Damascus has already become an extension of the Kremlin.