Most in International Relations today, whatever their view of structural realism, would agree with Robert Jervis that Waltz’s theory is “the most truly systemic of our theories of international politics.” I argue that it is, in fact, the antithesis. Waltz, despite his systemic starting point, produced an analytic theory. Waltz’s redefinition of a system as “composed of a structure and of interacting units” replaced the “systemic” understanding of a system as parts of particular types related in particular ways to make a whole with emergent properties with an analytic model of characterless units interacting with one another and with a reified structure. Waltz, I argue, was led to this stunning reversal by his application of: a levels and units frame; a reified conception of structure; a mistaken exclusion of the attributes of units that make them parts of the system; a vision of systems as derivative constraints on otherwise more or less autonomous units; and certain peculiar ideas about the nature of theory. In the final section, I argue that “relationalism” today is not merely reviving, but extending, “systemic” approaches in International Relations and is now poised to make the sort of transformative contribution that Waltz promised but did not deliver.