National tax policy is one product of the classic Lockean social contract between individuals and government. But countries are now so economically interdependent that one nation's tax policies can profoundly undermine another's attempts to implement the bargain. This article argues that tax experts from the United States and its peer countries are implicitly drafting a transnational social contract that potentially constrains national tax policy bargaining. I identify the existence and terms of this implied contract, analyze it from a political philosophy perspective, and argue that meaningful debate about tax policy must address how principles arise and are implemented as well as whether the chosen principles are appropriate. I conclude that if an international social contract exists, its terms should be explicitly articulated so that national responsibilities to the international community can be acknowledged and confronted in domestic tax policy deliberations.
