Imagine that you are Bashar al-Assad. Primarily due to the assistance of Russia, Iran, and Hezbollah, you have prevailed in the civil war–at least in the western part of the country. But what do you do now? Syria is a smoking ruin. Millions of refugees have taken their talents to Turkey and Europe, and they aren’t coming back in the foreseeable future. There are American troops in the eastern part of the country, and the Kurds are effectively in charge; your writ doesn’t run there. The Russians and Iranians have neither the resources nor the inclination to finance a reconstruction effort or a reconquest of the east, and you’re hardly in a position to ask America, Europe, or the Gulf states for help. How do you win the peace?
Realistically, you probably can’t, but there are two things you can try. First, you can acknowledge reality and make a deal with the Kurds which gives you nominal sovereignty, and them practical control of the region, at least for now. That should get the Americans out, and you can deal with the Kurds when conditions are more favorable at a later date. Second, you can pretend to support legitimate efforts at national reconciliation, and offer to take those troublesome refugees back, in exchange for aid. That is unlikely to work, because no one with any sense trusts you, but what else do you have to offer?