Syria, Iraq (with Iranian support), ISIL, Kurds and assorted internal factions and now Yemen with it's own complicated civil war with likely involvement from Iran, both meet a Saudi-dominated pan-Arab military coalition. Libya has internal problems. Al-Shabaab, Horn of Africa. Boko Haram, Nigeria and other places, links with ISIL. Al-Qaeda is still in there somewheres. There is now effectively a war-zone that extends from northern Africa to Iran. The main fracture lines are Sunni-Shia Islam, Kurd-Arab-Persian, and state-to-state. Add to this that Israel just re-elected a leader who promises no peace with the Palestinians and another dimension could soon be added to this conflict.
Bets are off.
The West does not and cannot control how events unfold from here.
Canada's contribution will have no effect.
Incidently, consideration of international law now has no influence in how the Harper government employs the Canadian Forces. That part is actually a very serious problem for us and for the Canadian Forces. I'm no expert (Dave?) but I don't think this puts a Canadian commander (or their charges) ordering combat missions into Syria on firm legal ground. "Everybody else is doing it" has never been a legal defence.