Recent work in the trade-conflict literature has mainly focused on the dyadic relationship between interdependent states. Drawing on the rationalist explanations of pacific behavior between trading partners, I propose a theoretical framework in which economic ties have political implications in foreign policymaking not only for economically interconnected states but also for third-parties to this relationship. I construct a model based on simple deterrence logic. This model explains conflict initiation and third-party intervention as related processes that can be understood with the same causal mechanism. I argue that extensive trade ties are informative for external actors about trading states’ willingness to join in with their partners in armed conflicts. Anticipating that the target will receive outside help, states are less likely to initiate against targets in an important interdependency relationship. Using a strategic probit model, I analyze initiation and joining behavior in militarized disputes between 1870 and 2001. This broad approach to the uncertainty-clearing effects of trade shows that states with significant economic ties are less likely to be targeted and intervention becomes obsolete in an interdependent world.