In any city in the world, an extremist could explode your subway car, yet surveillance and security are more advanced than ever. Ebola ravaged thousands for months and now Zika continues its creep around the globe, yet life expectancy and healthcare are more advanced than at any other time in human history. A slowing Chinese economy and falling oil prices warn of a global economic downturn, yet human civilization is richer and more developed than in the past. And while nuclear fears proliferate and our environment suffers, new regimes and technologies suggest reasons for cautious optimism. So what does it all mean? What do we really have to fear, and how should that drive our politics in this age of insecurity?