Ideology may directly provide motive and indirectly capacity for collective violence, thus making armed conflicts longer and bloodier. We investigate these propositions by drawing on an innovative global dataset which codes ideological claims by rebel groups and governments in intrastate armed conflicts since 1946. Results demonstrate that although ideology increases conflict duration, these effects vary by type and timing. Whereas secular ideological conflicts tended to be more protracted during the Cold War, religious ideology has become increasingly important since. We, however, find little evidence that ideology increases conflict intensity. Rather, rebel criminality best accounts for intensity. So, while immaterial resources like ideology sustain willingness to fight, ideology’s influence upon conflict intensity is limited, especially after the Cold War. Future studies need to take ideology seriously and need to investigate its characteristics more in-depth and in conjunction with material, identity related and international variables.

意识形态可能直接为集体暴力提供动机和间接能力，从而使武装冲突更加漫长和血腥。我们通过利用一个创新的全球数据集来研究这些命题，该数据集对自 1946 年以来反叛团体和政府在州内武装冲突中的意识形态主张进行编码。结果表明，尽管意识形态会增加冲突持续时间，但这些影响会因类型和时间而异。冷战期间世俗的意识形态冲突往往更加持久，而宗教意识形态自那以后变得越来越重要。然而，我们几乎没有发现意识形态会增加冲突强度的证据。相反，反叛犯罪最能解释强度。因此，虽然意识形态等非物质资源维持了战斗意愿，但意识形态对冲突强度的影响是有限的，尤其是冷战之后。未来的研究需要认真对待意识形态，需要更深入地研究其特征，并结合物质、身份相关和国际变量。