Cooperation among militant organizations contributes to capability but also presents security risks. This is particularly the case when organizations face substantial repression from the state. As a consequence, for cooperation to emerge and persist when it is most valuable, militant groups must have means of committing to cooperation even when the incentives to defect are high. We posit that shared ideology plays this role by providing community monitoring, authority structures, trust, and transnational networks. We test this theory using new, expansive, time-series data on relationships between militant organizations from 1950 to 2016, which we introduce here. We find that when groups share an ideology, and especially a religion, they are more likely to sustain material cooperation in the face of state repression. These findings contextualize and expand upon research demonstrating that connections between violent nonstate actors strongly shape their tactical and strategic behavior.

中文翻译：

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盗贼中的荣誉：了解暴力非国家行为者之间的修辞和物质合作

激进组织之间的合作有助于提高能力，但也存在安全风险。当组织面临来自国家的大量镇压时，情况尤其如此。因此，要让合作在最有价值的时候出现并持续下去，激进组织必须有办法承诺合作，即使背叛的动机很高。我们假设共享意识形态通过提供社区监控、权威结构、信任和跨国网络来发挥这一作用。我们使用关于 1950 年至 2016 年激进组织之间关系的新的、广泛的、时间序列数据来测试这一理论，我们在这里介绍这些数据。我们发现，当群体共享一种意识形态，尤其是一种宗教时，他们更有可能在面对国家镇压时维持物质合作。