Quantitative research has established a strong association between ethnopolitical exclusion and civil war onset, but direct investigation of the proposed causal pathway has been limited. This article applies large-N qualitative analysis (LNQA) to 15 post–Cold War cases to trace how exclusion may generate grievances, mobilization, and conflict escalation. In nine cases, grievance-based mobilization preceded civil war, and escalation followed governments’ reliance on indiscriminate repression or on inconsistent mixes of rejection and accommodation. In six cases, however, conflict itself produced exclusion, revealing recursive dynamics rather than a one-way sequence. These findings refine grievance theory by showing that escalation is shaped by patterns of state response and that exclusion may also emerge as a result of violence. More broadly, the study demonstrates how systematic qualitative analysis across multiple cases can trace mechanisms, address concerns about endogeneity and measurement validity, and still support cautious generalization.