Terrorism is as old as history and almost certainly older. In 68 B.C., for instance, the Roman city of Ostia, a vital port for one of the world's earliest superpowers, was set on fire by a band of thugs. They destroyed the consular war fleet and, rather embarrassingly, kidnapped two leading senators. Panic ensued—the same panic that has now been recapitulated down the centuries, courtesy of such terror groups as the Irish Republican Army, the Palestine Liberation Organization, the African National Congress, the Liberation Tigers of Tamil Eelam, al Qaeda and, most recently, ISIS. At the time of writing this article, the world had witnessed three major terrorist attacks within a period of 20 days—Beirut, Paris, San Bernardino—which were quickly followed by additional atrocities in Istanbul, Kabul, Dikwa, Nigeria, and elsewhere, each committed by Islamic extremists. And just as 19th-century German historian Theodor Mommsen described the culprits at Ostia as “the ruined men of all nations” forming “a piratical state with a peculiar esprit de corps,” political leaders today typically resort to describing terrorists as insane, deranged or purely evil.