Book excerpt: G-Zero -n.A world order in which no single country or durable alliance of countries can meet the challenges of global leadership. Come the worst - a rogue nuclear state, a pandemic, complete financial meltdown - where would the world look for leadership? A generation ago Europe, the US and Japan were the world's powerhouses; the free-market democracies that propelled the global economy. Today they struggle just to stay on their feet, and there appears to be nobody to step into their shoes. Acclaimed geopolitical analyst Ian Bremmer argues that the world is facing a leadership vacuum- our need for cooperation has never been greater, but the G20 members are poised for uncertainty and open conflict. Yet all is not lost. Bremmer shows where positive sources of power can still be found, and how they can be excercised for the common good. 'Fascinating and important . . . combines shrewd analysis with colourful storytelling to reveal the risks and opportunities in a world without leadership.' Fareed Zakaria, editor-at-large for Timeand author of The Post-American World 'An essential navigational guide in the new leaderless world.' Sir Martin, CEO, WPP