The number of radical Islamist groups fighting in civil wars in Muslim countries has steadily grown over the last twenty years, with such groups outlasting and outperforming more moderate groups. By 2016, Salafi jihadist groups accounted for most of the militant groups in Syria and half of such groups in Somalia. In Iraq, a third of all militant groups were composed of Salafi jihadists. Many analysts argue that the rise of these groups reflects an increase in radical beliefs in Muslim societies. Under certain conditions, however, rebel leaders have strong incentives to embrace an extreme ideology even if they do not believe the ideas that underlie it. When competition is high, information is poor, and institutional constraints are weak, an extremist ideology can help rebel leaders overcome difficult collective-action, principal-agent, and commitment problems. All three of these conditions have been present in the post-2003 civil wars in the Middle East and Africa, and all help explain the emergence and growth of radical groups such as the Islamic State and al-Qaida.

中文翻译：

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极端主义者在内战中的优势

在过去的二十年里，在穆斯林国家内战中战斗的激进伊斯兰团体的数量稳步增长，这些团体的持久性和表现优于温和的团体。到 2016 年，萨拉菲圣战组织占叙利亚激进组织的大部分，在索马里占此类组织的一半。在伊拉克，三分之一的激进组织由萨拉菲圣战分子组成。许多分析家认为，这些团体的兴起反映了穆斯林社会激进信仰的增加。然而，在某些情况下，反叛领导人有强烈的动机去接受极端意识形态，即使他们不相信其背后的思想。当竞争激烈、信息匮乏、制度约束薄弱时，极端主义意识形态可以帮助反叛领导人克服困难的集体行动、委托代理、和承诺问题。所有这三种情况都出现在 2003 年后中东和非洲的内战中，它们都有助于解释伊斯兰国和基地组织等激进组织的出现和增长。