Antagonist
Character Role Analysis
The Terrorist Group, Until...
This one seems pretty obvious. When you have a group of terrorists in a novel, you typically have your antagonists right there. And that's exactly how things are at the beginning of Bel Canto.
But Patchett cleverly shifts the ground under our feet: as the novel goes on, we see more and more things to like about this particular group of freedom fighters. They're much less violent than usual terrorists; in fact, they don't kill anyone at all. They're genuinely trying to do something good for their fellow citizens. They like to play chess and soccer (what could be more likable?). They grow to love opera. They're nicer and nicer to the hostages, and friendships begin to form.
As a strange community blossoms in this weird scenario, the novel basically blurs the lines on who the protagonists are. By the end of the novel, when the government forces break in and start shooting, the novel almost seems to be saying that the whole community living in the house (terrorists and hostages alike) are the protagonists, and the government forces violently disrupting their world are the antagonists. Trippy, huh?
There may be plenty of questions to ask about that. Is it actually the most reasonable or ethical way to think about the scenario? Do we actually buy it as something that might happen in the real world? Are we comfortable with that transition as a metaphor? But the book is pretty successful in making the transition happen, even if it's a little fuzzy morally or unrealistic. Don't argue with the fiction, fellas.