Napoleon III's 1860s intervention in Mexico mystified some British observers. For many others, however, it raised urgent questions about the duties of European civilization and the future of global order. This article argues that the affair forced attitudes toward other European countries' overseas imperial projects into sharp political focus, and that in doing so it revealed incipient shifts in the center of gravity of Victorian liberalism. France's Second Mexican Empire split opinion in the Liberal Party and press, throwing light on wider disputes about the parameters of legitimate imperial intervention, the reach of the principles of nationality and self-determination, the political needs of disordered multiracial polities in less-developed parts of the world, and Europe's proper relations with Spanish America. But most Liberals who engaged with the enterprise condemned it, a fact that lays bare a changing balance of power between what historians have called “liberal imperial” and noninterventionist arguments in the 1860s. The failure of the intervention, moreover, did much to affirm powerful partisan narratives about French politics, which helped to buttress the electoral ascendancy of the Liberal Party.

拿破仑三世在 1860 年代对墨西哥的干预令一些英国观察家感到困惑。然而，对于许多其他人来说，它提出了关于欧洲文明的责任和全球秩序的未来的紧迫问题。本文认为，这起事件迫使人们对其他欧洲国家的海外帝国计划的态度成为尖锐的政治焦点，这样做揭示了维多利亚时代自由主义重心的初步转变。法国的墨西哥第二帝国在自由党和媒体中出现分歧，引发了关于合法帝国干预的参数、民族和自决原则的范围、欠发达地区无序的多种族政治的政治需求等更广泛的争论世界，以及欧洲与西班牙美洲的适当关系。但参与这项事业的大多数自由主义者都谴责了它，这一事实暴露了 1860 年代历史学家所称的“自由帝国主义”与不干涉主义论点之间不断变化的权力平衡。此外，干预的失败在很大程度上证实了关于法国政治的强大党派叙事，这有助于巩固自由党的选举优势。