This article offers a realist interpretation of Tacitus’s analysis of political failure. Tacitus described the early Roman Empire as a balance between the conflicting and irreconcilable values and interests of the emperor, the army, and the senate. For him Stoic-republican morality in itself—without the intervention of a political standard demanding political agency in every circumstance—cannot provide an all-purpose guide to action. He provides a fine-grained analysis of types of political failure, such as failing to act, or to realize one’s limited (...) scope for maneuver, or the inevitability of failure given particular political circumstances. Tacitus also describes Thrasea, a moderate member of the senatorial opposition to Nero, as an exceptionally laudable figure. His preference for moderate politics places Tacitus on the side of contemporary status-quo oriented, liberal, realists (e.g., Bernard Williams), rather than on the side of radical realists (e.g., Raymond Geuss, Enzo Rossi), but the central lesson of his understanding of Roman politics is not so much that political order is fragile as that the cost of political failure can indeed be unbearably high. (shrink)