Does the dramatic rise of plural citizenship portend a postnational future? This essay describes how plural citizenship both reflects and accelerates postnationalism, in the sense that it undermines state-based identities. This proposition may pose an initial paradox, insofar as plural citizenship could be thought to facilitate state-based connections. But acceptance of plural citizenship is likely to lower the intensity of the citizen-state affiliation and, in turn, the intensity of bonds among citizens. A citizenship regime tolerant of dual citizenship will count more members who subordinate the attachment to other national attachments, as an inevitable corollary of the move from an exclusive to a non-exclusive relationship. States, however, have incentives to accept plural citizenship notwithstanding these identity-diluting effects. Moreover, insofar as international norms begin to require acceptance of plural citizenship, at least in some cases, states will be increasingly constrained from rejecting the status at the same time that acceptance may result in constitutive challenges to the state as a form of community.