Political Instability and the Failure of Deterrence

To study the conceptual foundations of deterrence, we develop a model of an international crisis between a country seeking to maintain a peaceful status quo (Defender), and a potential aggressor (Attacker). Attacker's leader is politically insecure and may be unseated by domestic elites. Leaders and elites can each be hawkish, benefiting from conflict, or dovish and prefer peace. We show that the ability to maintain peace through deterrence crucially depends on ideological cohesiveness within Attacker countries. When there is ideological disagreement, we identify two novel mechanisms that cause the conventional logic of deterrence to fail. First, political instability breaks the link between a leader's aggressive actions and Defender's retaliatory response. Second, political instability creates a commitment problem leading doves to initiate crises to quell domestic conflicts. Asymmetric information exacerbates these problems so severely that Defender is better off committing to complete inaction.