Larry Diamond, a lifelong scholar of democracy, examines the history of its struggles and its future. The defence of democracy has relied for decades on U.S. global leadership, including its alliances with advanced democracies in Europe and Asia. But, he warns, if America does not reclaim its traditional place as the keystone of democracy, today's global authoritarian trend will accelerate. But there is hope - Diamond offers concrete, deeply informed suggestions for policymakers and citizens alike to turn the tide and usher a new age of democratic renewal.