Intelligent people already know why: Iran is interested to see Shiite Muslim groups proliferating, for religious as well as practical reasons.
Iran is the leader of the Shiite world, in the same vein Saudi Arabia represents the Sunni world.
This is why Iran supports Hezbollah (Shiite) over other groups in Lebanon, Houthis (who are not Shiite but oppose the Sunni majority) in Yemen, Shiite in Iraq, Bashar Al Assad (who is Alawite himself but closely aligned with the Shiite and opposing the Sunnis in Syria). The only place where Iran supports Sunnis is Gaza, and that's done to primarily weaken Israel which Iran perceives as its primary threat to regional hegemony.
flyinglizard|6 years ago
This is why Iran supports Hezbollah (Shiite) over other groups in Lebanon, Houthis (who are not Shiite but oppose the Sunni majority) in Yemen, Shiite in Iraq, Bashar Al Assad (who is Alawite himself but closely aligned with the Shiite and opposing the Sunnis in Syria). The only place where Iran supports Sunnis is Gaza, and that's done to primarily weaken Israel which Iran perceives as its primary threat to regional hegemony.