International law does not address intelligence activities explicitly, and many scholars assume that international law has no effect on the practice of intelligence. Yet, international courts and bodies have recently started to hold states to account for internationally wrongful acts resulting from intelligence cooperation. This chapter analyses the effects of recent instances of state accountability on state decision-making, using a modified rational choice model accounting for the boundedness of state rationality. It shows that these instances of state accountability have changed the payoffs and costs of intelligence cooperation. States must now take into account the risk of accountability, and considerations of international legality may now outweigh domestic considerations. The chapter therefore argues that recent instances of state accountability before international courts and bodies have constrained states’ freedom in intelligence cooperation, thereby serving their national security interests. Existing research shows that respect for the rule of law is necessary to an effective fight against national security threats, and that measures violating human rights or undermining the rule of law are counter-productive. Hence, the chapter further argues that these recent instances of state accountability increase states’ respect for the international rule of law, leading them to protect their national security more effectively.