Two players choose hawkish or dovish actions in a conflict game with incomplete information. An extremist, who can either be a hawk or a dove, attempts to manipulate decision making. If actions are strategic complements, a hawkish extremist increases the likelihood of conflict, and reduces welfare, by sending a public message which triggers hawkish behavior from both players. If actions are strategic substitutes, a dovish extremist instead sends a public message which causes one player to become more dovish and the other more hawkish. A hawkish (dovish) extremist is unable to manipulate decision making if actions are strategic substitutes (complements).