There is no chance of reaching a political agreement and a calm in Syria as long as the Iranian military presence in Syria continues and the Iranians are the ones calling the shots.
[source : A message to Putin: No calm in Syria as long as Iran calls the shots, Ynet News, https://www.ynetnews.com/articles/0,7340,L-5052290,00.html, 5th December 2017]
So let's just recap why Iran is in Syria.
Iran was invited into Syria after the USA, Israel and Saudi Arabia unleashed the worst international cutthroat Jihadis onto Syria as Plan B of a plan for war and regime change in seven countries in five years which was revealed to General Wesley Clark shortly after 9/11. Iran is fighting these Jihadis alongside Russia and Hezbollah. All three were invited into Syria by Assad.
But America, on the other hand, has been assisting these Jihadis, and even though the Jihadis are on the verge of total defeat, America has decided to stay in Syria, even though they were not invited in the first place.
And that is after Bomber Trump tweeted Obama dozens of times to stay out of Syria.
Infowars are more concerned about soya.