There are a few things, I think not. I don't consider it to be moral superiority, it is more a Europeaness in most cases. It makes us very different from the United States.
Canada has little history of imperialism outside of its own borders, and the little that is there most don't know about.
We have a reputation for punching above our weight internationally. That goes back to when we were just a colony, but became very prevalent during the first and second world wars. It continued right up through the Trudeau years through our work with the UN.
We are not war-like. Our country does not go to war easily, but when we do, we do a very good job of it. We've never had a real civil war. There was the Riel Rebellion, but that was far from all out war.
We have a tradition of social justice and equal rights. We've generally had less racism than most places. We've accepted more people from more places than other nations and we've encouraged them not just to keep their cultural identities, but to share them. We got rid of the death penalty long ago. We've been a leader in women's rights.
We are a wealthy nation and we got that way without as much of the cruelty to others so often seen in the histories of other nations.
There's a lot more, but that should give you an idea. Canadians are not like Americans and don't want to be like Americans, though Americans and some Canadians (those Harperites again) think we should.
The result is that when we see something wrong, we speak out. We have every right to because we have a lot of experience at being right.