Then they should do their own thing in Europe where they came from.
Syria is a playing field, it has been so for quite some time now. The major players were/are Russia, Iran, Turkey, USA and Israel. The crisis in Ukraine has a connection to the crisis in Syria. Israeli supporters in the US have, for quite some time now, wanted a Middle East where Israeli military will be the dominant force. After Iraq was taken out, the campaign against Syria intensified and Syria was almost taken out, if it were not for Russia. Russia stepping in and saving Syria from the wrath of Israeli lobby in the US infuriated the Israeli supporters in the US government. To punish and distract Russia, legally elected government in Ukraine was overthrown and a dictator called Zelensky was installed; the objective was to start an arm conflict with Russia so that Russia will not be able to support Syria any longer. I would like to point out that Israeli lobby is not the only one which was interested in Russia's demise, there were other actors as well, not only in the US but in the West in general, who were eyeing for Russia's vast natural resources. Once Russia was sufficiently distracted in Ukraine, the campaign against Syria intensified again. This time, Iran stepped in to assist Syria.
By this time, it had become quite clear to both Russia and Iran that Syria was more of a liability than asset. Syria as a country has been fractured long time ago, you could blame Israel and its supporters in the US but at the end, it was up to Syrians to fight and defend their country but they failed to emerge as a cohesive united force. Because of this, both Russia and Iran decided not to help Syria.
Israel
Israel benefited a great deal from this coup, at least, for the time being. Israel is in possession of Syrian oil fields that generate revenues for Israel. Also, in addition to oil fields, Israel may grab more land. As a bonus, Iran will not be able to supply Hezbollah. This will create a breather for Israel. More importantly, Israeli supporters in US government will have more leverage against Russia.
Iran
This was a major setback for Iran. Iran will have no influence in shaping up the region going forward unless Iran is able to develop rapport with one or more factions of the rebels that are in control of Syria now. Iran will not be able to fight a proxy war against Israel.
Erdogan
Erdogan has been feeling like he was being under valued for quite some time now. He was itching to show his importance to Russia and Israel. Erdogan has emerged as the king maker for now. Two of the major rebel groups HTA and SNA are Erdogan's proxies. I do not know how long Erdogan will be able to control these rebels!
Kurds
Kurds are used by Israel and its supporters in the US government as a leverage against Erdogan. Interestingly, no one trusts Erdogan. This is going to be a future flash point which will break the unitty of Syrian rebel groups. This will also infuse unpredcitiblity that can be harmful to the countries in the vicinity.
Syrians
Syrians who are comitted to the Syrian statehood are going to lie low. They may even melt into Iraq for the time being. The Syrian military equipments that Israel is destroying can be rebuilt very quickly. Syria as a credible military threat to Israel has ceased to exist very long time ago. This coup had more to do with Iran than Syria.
Russia
Russia's main objective will be to neutralize Ukrain as a credible military threat. So that, Ukraine will never be used to distract Russia from its future strategic objectives. I strongly believe that Russians understand that it will be a major blunder to stop the Ukraine war without liberating the traditional Russian territories that are in Ukrainian possession right now.
Future for Syria
The major crisis is on the horizon. I feel very sorry for Syrian people. However, they chose to fight among themselves instead of putting up a united front against their enemy. As a result, this was bound to happen.