Going by the Vietnam example,how long should it take Northern Syria to regain Southern Syria,i.e. Palestine?

Palestine has been a region of Syria since at least the time of Herodotus circa 500 B.C. It was severed by the French and the British in 1920. So it should come as no surprise that Palestinian resistance to the US/israeli occupation is historically based in Damascus. But how long will it take to liberate Palestine and restore it to the Syrian homeland?