Efforts to foster improved international tax cooperation have become preoccupied with tax harmonization. Deharmonization offers the possibility of harmony without uniformity. By exploring two examples of tax deharmonization in practice and considering the origins and limitations of tax harmonization, this Article brings the traditional emphasis on harmonization into question. It then makes the case that deharmonization--cooperation without uniformity-- could provide a viable alternative. Achieving tax deharmonization's potential would require revisiting some of the most basic elements of our current international tax regime, particularly the benefits principle.