States must navigate the structure of the international system in their relations with other states. One crucial component of this structure are rivalries as they indicate latent threat to states. Rivalries should thus influence how states behave within the given system, but also how they seek to shape and restructure it. Focusing on arms transfers, we clarify how the systemic structure implied by rivalries drives states’ efforts to engage in security cooperation with other states. Intuitively, a rivalry with another country should diminish an exporter’s propensity to transfer weapons there. But what is more, we argue that rivalries outside of this focal dyad matter as a potential importer’s enmity towards other countries will reveal information about its security interests to the exporter. Specifically, sharing rivalries with the same set of countries will signal to the exporter that there is a congruence in security interests and thus facilitate security cooperation. This security cooperation should take the form of arms transfers, at least if exporters value buck-passing and fear entrapment. We test our expectations using original data on Major Conventional Weapons transfers in the Interwar years, a period where this condition likely holds, and inferential network analysis models. Sharing rivals increases two countries’ probability to trade arms whereas a rivalry between countries exhibits no effect. This research contributes to our understanding of security cooperation, the arms trade, and networked international relations.

各国在与其他国家的关系中必须驾驭国际体系的结构。这一结构的一个重要组成部分是竞争，因为它们表明对国家的潜在威胁。因此，竞争不仅会影响国家在既定体系内的行为方式，也会影响它们塑造和重组体系的方式。我们以武器转让为重点，阐明了竞争所隐含的系统结构如何推动各国努力与其他国家开展安全合作。直觉上，与另一个国家的竞争应该会降低出口商向该国转移武器的倾向。但更重要的是，我们认为，这一焦点二元之外的竞争很重要，因为潜在的进口商对其他国家的敌意将向出口商泄露有关其安全利益的信息。具体而言，与同一组国家共同竞争将向出口国发出安全利益一致的信号，从而促进安全合作。这种安全合作应该采取武器转让的形式，至少如果出口商重视推卸责任并担心陷入困境的话。我们使用两次世界大战期间（这一条件可能成立的时期）主要常规武器转让的原始数据以及推理网络分析模型来测试我们的预期。共同的竞争对手会增加两国进行武器贸易的可能性，而国家之间的竞争则不会产生任何影响。这项研究有助于我们理解安全合作、武器贸易和网络化国际关系。