The composition of the Group of Twenty or G20 reflects the metamorphosis of world politics. In contrast with other 'Gs' (G8, G77) its members are both developed and emerging economies, democracies and authoritarian regimes, secular and religious governments. This book argues that the G20 is neither a global executive board for a new world order, nor is it just a crisis unit for failing economies. It is a laboratory for the observation, experimentation and invention of new forms of international cooperation that are redefining global politics.