How can an international organization be made adaptable? Having been designed to fulfil a specific mandate, international organizations should disappear from the world stage once .the initial conditions that led to their establishment no longer exist: their constituents (governments or activists) will not support them when their mandate becomes obsolete or their added value is reduced. Nonetheless, they survive external shocks, resource traps, and even the growing indifference of their founding fathers. The explanation lies in their successful resistance to constituents' control; counter-intuitive adaptation to external change; unplanned expansion through mandate enlargement; and a snowballing albeit unintentional trend to build up networks. Overall, the relative success of international organizations can be measured as a global balance between performance and resilience, exploitation and exploration, autonomy and cooperation. To reach that balanced stage they must be altogether dualistic (coupling the technical with the political); adaptive (converting slack into innovation); organic and ambidextrous (setting new challenges while pursuing current activity). Since they combine components that come from local, national, regional and transnational recipes for survival and performance, they are complex hybrids made up of public agencies, private firms, third sector associations, and expert, activist, or lobbying interest groups.