Pooty-poot wanted to drive the jihadists into Europe, and he succeeded. He wanted to test NATO's resolve and bully Turkey, and that gave him mixed results. He wanted to come to a deal with the Saudis over oil production, and wanted Iran involved, and failed miserably. The civil war is still going on; areas temporarily cleared of rebels will fall out of regime control once again. The economy is back to the stone age. Almost five million Syrians fled the regime and/or the fighting, living now in Jordan, Turkey, and Lebanon, and in no hurry to go back. Iran used Russia's presence as a pretext to skedaddle, so no more help there (Syrian intervention was very unpopular in Iran, also among Iran's hizzie proxies from Lebanon, and the foreign nationals Iran press-ganged into serving). Worst of all, the war was very expensive, right at the time the Russians could least afford it -- one big reason Vlad the Imploder launched their overseas adventure.
“Almost five million Syrians fled the regime and/or the fighting, living now in Jordan, Turkey, and Lebanon”
And Germany and Greece and Sweden and......