A decade ago the world was struggling with the repercussions of the global financial crisis in 2007 and 2008 that emerged in the interconnected transatlantic financial system. At this critical moment in time, the G20 was elevated from a meeting of finance ministers and central bank governors to the level of heads of states and government. By including a number of rising as well as middle powers non G7 countries the first G20 summit in Washington in November 2008 made clear that current cross-border challenges cannot anymore be dealt with by the old powers of the traditional establishment. At the subsequent summits in London (April 2009) and Pittsburgh (September 2009) the G20 displayed an astonishing level of international cooperation by agreeing on wide-ranging commitments that helped to calm down international financial markets and strengthen the crisis response of international financial institutions. These early initiatives led some optimistic observers to conclude that the system worked.