It depends. In a democracy the assumption is that once the vote of yea or nay happens everyone will support the side that wins. The way it actually works, as you point out, is one side will try to exploit political advantage with the intent to create a policy failure which will allow a political advantage during the next election for their own party. So the nation suffers as a whole.
Which leads me to point two, if the violent act is committed by a non state actor(s) it may be best to treat it as a Law Enforcement problem as opposed to a lets invade every country and turn them into a democracy problem.