This chapter evaluates the successes and failures of the world government movement after the Second World War. It focuses on the work of the World Association of Parliamentarians for World Government (WAPWG), which advocated a world parliament to ensure that postwar international governance represented the democratic wishes of the international body politic. The chapter assesses the WAPWG's place in the broader firmament of world government organizations and the wide but uneven support for the idea of a world parliament in both the British Conservative and Labour parties. It examines how world parliamentarians confronted nuclear proliferation, UN reform, Commonwealth relations, and Cold War politics. The WAPWG’s informal structure allowed its members to speak freely and to build an autonomous transnational movement. What world government advocates gained by being freed from institutional constraints, however, they lost in a lack of access to resources and the organizational scale that allowed UN staff to participate in large and lasting international initiatives.