ABSTRACTThis article investigates how members of US Congress legitimized their votes in four cases of military interventions after the Cold War (Iraq 1991, 2002–2009, Somalia 1993, Libya 2011). Using an original dataset on congressional rhetoric, the qualitative content analysis highlights that the domestic legitimization of military interventions hinges on members of Congress’s perception of external threats and national interests. So far, international relations research focused on the executive and the war powers literature offered mainly quantitative accounts on voting patterns within the legislative branch―especially for the US case. The relevance of national interest arguments within congressional debates confirms the expectations of neoclassical realism while contradicting previous studies about a dominant discourse in US society, which legitimizes interventions with universal values, such as democracy promotion or human rights.