Sure, they need to keep trying to be their best, rather than acting as if the other party's evil justifies acting as bad as they imagine the other being.
IMAGINE IF YOU WILL, YOU'RE PLAYING A SPORTS GAME WHERE THE OPPOSING TEAM GET TO ACT AS THE REFEREE. AND THE FIRST THING THEY DO WHEN THE GAME STARTS IS TO SLANDER YOU AND THEN THROW OUT THE RULE-BOOK.