This paper attempts to demonstrate how Philip Roth in The Plot Against America utilizes the manipulative function of Moral Duty to further the development of the plot, both as a literary term, and as a conspiracy. It becomes evident that Roth, by tracing the philosophical roots of the concept of moral duty, does not only concur with how this concept is defined, as shown in his portrayal of his characters, but he also develops this concept. He does that in such a way that enables him to present the plot, in both of its senses, as a moral time loop, which ends as it begins. Thus, this paper follows a moral approach towards his novel, The Plot Against America, in order to discern the different patterns of duty-driven manipulation, which set the plot into a nonlinear track of narration that is phased through an older narrator, recounting the memories of his younger self in an alternative historical timeline.