Humanitarian military interventions characterized the political atmosphere of the 1990slegitimizing the phenomenon in which third-party actors use force to end intrastate abuses. While calls for humanitarian military intervention remain numerous, the phenomenon itself is laden with grave skepticism given the large "selectivity gap" in mission patterns. While states and institutions appear to enforce the Responsibility to Protect (R2P) in reaction to some internal conflicts such as Kosovo, Bosnia, and Libya, they withhold similar policy options in cases of more intense armed conflict, as in Darfur, Syria, and Myanmar. Much of the research focuses on dichotomous explanations -suggesting that either ethical norms or geopolitical strategies guide patterns of such third-party interventions, but I demonstrate that the "selectivity gap" of humanitarian military interventions is primarily driven by variations in regional institutions and conflict perceptions.Such regional dimensions lead to more probable pathways of intervention within the West, founded upon value-based institutional resources as seen within NATO and EU structures. This project contributes to both theoretical and empirical debates within international relations and security studies. It introduces a new dataset that offers the first quantitative and systematic analysis of humanitarian military interventions, including 1,110 observations of intrastate armed conflict between 1987-2016, paired with a range of international responses, nonresponses, and key theoretical variables. In addition, it introduces an Intervention Index that accounts for the intensity of military interventions across different cases of humanitarian crisis.The aggregated models founded upon this data highlight the importance of regional neighborhoods and conflict perceptions in activating third-party responses, leading to three novel pathways of humanitarian intervention. Using original-language NATO, US, EU, and Balkans archival records and leadership dialogues, I then process-trace how conflict perceptions across Western audiences