Ultimatums, bargaining, and the duty to preserve alternatives to war

Abstract

When can states justly make ultimatums? How should the recipients of ultimatums respond to them? This manuscript argues that because bargaining behavior like ultimatums and redlines causes war by generating bargaining failure, these behaviors should be scrutinized in the same ways that overtly aggressive acts like invasion are examined. It then argues that parties have a general duty to avoid eliminating alternatives to war. Ultimatums can only be justified if they satisfy the just war criteria of just cause, necessity, and proportionality. Likewise, the decisions to reject ultimatums can impair later claims that a state is fighting justly if they do not reflect the same criteria.