When the Millennium Development Goals (MDGs), the world’s biggest promise ever, were embraced by 189 nations in 2000 as a unifying framework towards the goal of development and poverty eradication, their true potential to shape development norms was not known to the world. Since then, the MDGs, their weaknesses notwithstanding, have transformed political agendas, shaped intersectoral action, forged global consensus and helped to catalyse partnerships between governments, development partners and civil society. They have been a tool to foster consistency within domestic policy—a key gap in developing country polity, and one that threatens reform—and contributed to making development assistance predicable. Often they have served as instruments for debt relief in poor countries. Their leverage has been unprecedented.