Information plays a critical role in theories of interstate behavior. This dissertation examines the question: how does domestic politics structure and condition the role of information in international conflict? In the first essay, I test an observable implication of audience cost theory by exploiting elections as a way to identify variation in the costliness of interstate signaling, under the assumption that election-year threats are more costly than threats made in non-election years. I find evidence consistent with audience cost theory in the behavior of democratic targets, but fail to find similar results for targeted autocracies. The findings overall suggest variation in domestic political institutions can explain whether and when information about threat credibility is received and interpreted by target states. In the second essay, I examine a previously untested assumption of diversionary war theory by investigating whether and how initiation status affects the public’s propensity to rally ‘round the flag. Using a survey experiment with researcher manipulation of initiation status, I find heterogeneous rallies across partisan identification, with rallies limited to in-partisans under the initiation condition, but widespread rallies across the full sample when a leader is seen as responding to foreign provocation. In the third essay, I develop conventional diversionary theory in two ways. First, I argue that diversion is fundamentally the manipulation of foreign policy salience, and that this objective is generally accomplished through actions short of war. Second, I argue that domestic constraints—specifically, a country’s media system and the flow of information between elites and citizens—condition the ability of leaders to reap the rewards of diversion. The results provide tentative support for the theory, and are consistent with media systems playing an important role in conditioning and structuring the relationship between domestic unrest and conflict.