While many of their practices are super secret, unknown to outsiders, the Alawites (the tribe the Assads belong to) trace their origins to Ali (and shiism). Hence the soft spot for Iran. The sunnis, who compromise 80% of Syria but are dominated by the minority Alawites are ready for revenge... And they hate Hezbollah, Persians, etc....
Nigeria says troops destroy extremist camp, rescue 178 people (AP)
from the article: Assad's fall could deliver Lebanon to Iran and Hezbollah