Dividing the world in two groups of countries – developed and developing – remains deeply engrained. This bifurcation is increasingly problematic. It has led to deadlock in negotiations and equity concerns. This article traces parallel developments of differential treatment in the trade and environmental regimes. It demonstrates that in both regimes a radical shift is in the making, away from differential treatment for developing countries as a group, and toward individualized differentiation between countries based on objective, issue-specific criteria. The question is less whether China or Russia are developing countries. The challenge is to find criteria to differentiate between countries – both developed and developing – tailored to each negotiation or regime. Half a century after the start of decolonization, this may be the end of differential treatment for developing countries. Yet, ironically, it leads to more (not less) differentiation and, though not without risks, can make regimes more effective and equitable.