Aumann is a member in the Professors for a Strong Israel (PSI), a right-wing political group. Aumann opposed the disengagement from Gaza in 2005 claiming it is a crime against Gush Katif settlers and a serious threat to the security of Israel. Aumann draws on a case in game theory called the Blackmailer Paradox to argue that giving land to the Arabs is strategically foolish based on the mathematical theory. By presenting an unyielding demand, the Arab states force Israel to "yield to blackmail due to the perception that it will leave the negotiating room with nothing if it is inflexible".