Book Description: Astonishing in its scope and erudition, this is the magnum opus that Niall Ferguson's numerous acclaimed works have been leading up to. In it, he grapples with perhaps the most challenging questions of modern history: Why was the twentieth century history's bloodiest by far? Why did unprecedented material progress go hand in hand with total war and genocide? His quest for new answers takes him from the walls of Nanjing to the bloody beaches of Normandy, from the economics of ethnic cleansing to the politics of imperial decline and fall. The result, as brilliantly written as it is vital, is a great historian's masterwork.