This article reconstructs J. G. A. Pocock's debt to Hannah Arendt's political philosophy in The Machiavellian Moment and argues that her presentation of classical politics in The Human Condition and her account of the secular nature of American foundation in On Revolution were important sources for Pocock's analysis of American liberal insecurity. However, a contextualization of The Machiavellian Moment within Pocock's immediate intellectual and professional milieu indicates that he placed himself in critical relation to Arendt's civic republican theory and located her philosophy of history in the same spectrum as the American political tradition he sought to historicize. While they did share a similar perspective on the ethical and political value of locating oneself within a long historical durée, their different conceptions of the problem of continuity for secular political structures provides a crucial context for their disparate responses to the discourse of political crisis in the United States in the late 1960s and the 1970s.