Audience costs theory posits that domestic audiences punish political leaders who make foreign threats but fail to follow through, and that anticipation of audience costs gives more accountable leaders greater leverage in crisis bargaining. We argue, contrary to the theory, that leaders are often unaware of audience costs and their impact on crisis bargaining. We emphasise the role of domestic opposition in undermining a foreign threat, note that opposition can emerge from policy disagreements within the governing party as well as from partisan oppositions, and argue that the resulting costs differ from audience costs. We argue that a leader's experience of audience costs can trigger learning about audience costs dynamics and alter future behaviour. We demonstrate the plausibility of these arguments through a case study of the 1863–4 Schleswig-Holstein crisis. Prime Minister Palmerston's threat against German intervention in the Danish dispute triggered a major domestic debate, which undercut the credibility of the British threat and contributed to both the failure of deterrence and to subsequent British inaction. Parliament formally censured Palmerston, contributing to a learning-driven reorientation in British foreign policy.

中文翻译：

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政治、观众成本和信号：英国和 1863-4 年石勒苏益格-荷尔斯泰因危机

受众成本理论认为，国内受众会惩罚那些制造外国威胁但未能贯彻执行的政治领导人，而对受众成本的预期让更负责任的领导人在危机谈判中拥有更大的筹码。我们认为，与理论相反，领导者通常不知道受众成本及其对危机谈判的影响。我们强调国内反对派在削弱外国威胁方面的作用，注意到反对派可能来自执政党内部的政策分歧以及党派反对派，并认为由此产生的成本不同于受众成本。我们认为，领导者对受众成本的体验可以触发对受众成本动态的了解并改变未来的行为。我们通过对 1863-4 年石勒苏益格-荷尔斯泰因危机的案例研究证明了这些论点的合理性。帕默斯顿首相威胁德国干预丹麦争端引发了一场重大的国内辩论，这削弱了英国威胁的可信度，并导致威慑失败和英国随后的不作为。议会正式谴责帕默斯顿，促成了英国外交政策以学习为导向的重新定位。