Canada is knows as a honest broker, that's I agree. But -and for many reasons- it doesn't have a strong presence in international policy, it always play along with US and NATO.
but to answer the question:
- There are no "two sides". especially after 7 years it's not a domestic issue anymore, and the "sides" are more than I could count on two hands.
-We have already lost if we make the equation equivalent with two sides, it has never been, it will never be. it's not fair to consider the most brutal regime as a side.
-There's absolutely no turning back for Assad and his supporters, the last 7 years have proved that for them it's even beyond politics. there's no price for them to back off. They will keep their war machine running until the last one of them.
-Unfortunately, the opposition has failed to gain any political weight or respect in the course of the 7 years. to be fair, no one supported them or heard them. and now, it's fragmented and helpless.
But for sure there can be a replacement -honestly even the devil himself is a better choice- can be corrupted? yes. can be more brutal? no. especially if its a coalition of several sects.
-let's remember that this thing started as peaceful rise-up, a revolution that children were it's first martyrs, and It was led by the people, the ordinary citizens, no agendas no oppositions… even when the free army was first created, it was created by only free young men who had to defend their homes and families with whatever weapon they could use.
-I don't know how anything can help now. For years we have only asked for one thing, an air ban, to stop planes from dropping barrels and bombs (that applies for the regime and the Russians). but now it's even too late for that.
personally, I only wish that there's some sort of help to give what left of the innocent citizens a short break, I don't even dare to wish for peace.
Ps. sorry for the longs answer.
ps.s as you seem interested I encourage you to check out Ford's (the US ambassador to Syria until 2012) latest interview 19.06. it has some good insights.