Its a trope highly seen in many forms of media between rivaling groups/individuals, and a chronic one throughout history and present day. Just like "All that glitters isn't gold" (but our minds and hearts can shine far brighter), "Might makes right" (but do the ends justify the means?), "Don't judge a book by it cover" (Assume that your initial assumption may be wrong, does correlate a little to second chances), and the "Fear of unknown and change" (or keeping of status quo, if does not harm or restrict freedoms then it needs not be restricted). We all need to have have a leash to keep us from going to far (Anarchy/Chaos), but if its too short then we get (Rebellion from Oppression/Abuse of Power). In all cases though open communication is key, along with respect, responsibility, and trust. If all were to follow such keystones, then peace/world peace could be achieved. Even the golden rule can be a double edged sword if we do not know the motives of others, as good will between two, could be bad for others (Favoritism/Unequal Distribution).
You probably know a lot of this already, so I'm just rambling/preaching my observations, but complex and tangled situations often bring it out of me.