Every Nation for ItselfBy: Ian Bremmer G Zero \JEE ZEER oh\ n A world order in which no single country or durable alliance of countries can meet the challenges of global leadership. What happens when the G20 doesnt work and the G7 is history. If the worst threateneda rogue nuclear state, a major health crisis, the collapse of the global financial systemwhere would the world look for leadership? For the first time in seven decades, there is no single power or alliance of