Preface July 5, 1915 Police headquarters, Centre Street, Manhattan The bombs came in all kinds of packages. Often they arrived in tin cans, emptied of the olive oil or soap or preserves the cans had originally been manufactured to contain, now wedged tight with sticks of dynamite. Sometimes they were wrapped with an outer band of iron slugs, designed to maximize the destruction, conveyed to their target location in a satchel or suitcase, "accidentally" left behind in the courthouse, or the train station, or the cathedral. Many of those devices were time bombs running on clockwork mechanisms. The more inventive ones utilized a kind of hourglass device, releasing sulfuric acid into a piece of cork, the timing determined by chemistry, not mechanics: how long the acid took to eat its way through the cork, until it began dripping onto the blasting cap below. Many were swaddled in old newspaper pages. One of the most notorious bombing campaigns sent the devices through the mail, dressed up in department-store wrapping. And sometimes the bomb was just a naked stick of dynamite, with a fuse simple enough to be lit with the strike of a match, ready to be flung into an unsuspecting crowd.

Many bombs were delivered anonymously. But others were accompanied by missives sent to a local paper, or left on a doorstep: threats, intimations of further violence, delusional rants, and more than a few manifestos. The smaller bombs--the ones detonated by a storefront, a few notches up from fireworks--were the mobster version of an "account overdue" mailing: the big stick of the extortion business. A few came from clinically insane individuals without a cause, propelled toward the terrible violence of dynamite by their own private demons. But most of the explosions that made the national news during those years were expressions, implicit or explicit, of a political worldview. The political bombers were a diverse bunch: socialist agitators, Russian Nihilists, Irish republicans, German saboteurs. But of all the bomb throwers of the period, no group was more closely associated with the infernal machines--as the press came to call the bombs--than the anarchists. The forty-year period during which anarchism rose to prominence as one of the most important political worldviews in Europe and the United States--roughly from 1880 to 1920--happened to correspond precisely with the single most devastating stretch of political bombings in the history of the West.

Indeed, the whole modern practice of terrorism--advancing a political agenda through acts of spectacular violence, often targeting civilians--began with the anarchists. What was anarchism, really? Start with the word itself. Today the word anarchy almost exclusively carries negative connotations of chaos and disorder. But when the political movement first emerged in the middle of the nineteenth century, the word''s meaning was much more closely grounded in its etymological roots: an-, meaning no, and -archos, the Latin word for "ruler." The anarchists believed that a world without rulers was possible. At times, they convinced themselves that such a society was inevitable; imminent, even. The anarchists maintained that there was something fundamentally corrosive about organizing society around large, top-down organizations. Human beings, its advocates explained, oftentimes at gunpoint, had evolved in smaller, more egalitarian units, and some of the most exemplary communities of recent life--the guild-based free cities of Renaissance Europe, the farming communes of Asia, watchmaking collectives in the Jura Mountains of Switzerland--had followed a comparable template, at a slightly larger scale.

These leaderless societies were the natural order of things, the default state for Homo sapiens . Taking humans out of those human-scale communities and thrusting them into vast militaries or industrial factories, building a society based on competitive struggle and authority from above, betrayed some of our deepest instincts. At its finest moments, anarchism was a scientific argument as much as it was a political one. It had deep ties to the new science that Darwin had introduced, only it emphasized a side of natural selection that is often neglected in popular accounts: the way in which evolution selects for cooperative behavior between organisms, what Peter Kropotkin--anarchism''s most elegant advocate--called "mutual aid." As a theory of social organization, anarchism was equally opposed to the hierarchies of capitalism and the hierarchies of what we would now call Big Government. For this reason, it lacks an intuitive address on the conventional left-right map of contemporary politics, which partly explains why the movement can seem perplexing to us today. Whatever you might say about Emma Goldman and Alexander Berkman and Peter Kropotkin--the three main anarchists in this book--they should never be mistaken for free-market libertarians. They wanted to smash the corporate regime as much as they wanted to smash the state.

But the other confusion about the movement lies in the language itself. The main reason that the word anarchy now carries the implicit connotation of troublesome disorder is because a century ago, a wave of anarchists insisted on blowing things up, again and again and again, in the name of the movement. That sense of unruly chaos that the word anarchy triggers in our mind today is the aftershock of all those explosions, part of the debris field they left behind. For the anarchists, it was arguably one of the most disastrous branding strategies in political history. They turned a word against their cause. * * * Why exactly were the anarchists so intent on blowing things up? That is, by definition, a technological and scientific question as much as it is a question about radical ideologies: How did anarchism and dynamite--born in the same decade but otherwise unrelated--come to be so closely intertwined? Dynamite gave small bands of humans command of more energy per person than they had ever dreamed of having before. Dynamite, quite literally, gave them power. The anarchists happened to be the first political movement to embrace that new power.

But why were they compelled to make that choice? Could they have made a more persuasive case through less destructive means? To even begin to answer those questions, we need to understand where the anarchist''s appetite for political violence originally came from, its complex symbiosis with the everyday violence that industrialization had unleashed into the world. For every death at the hand of a bomb-wielding anarchist, a hundred or more would die from factory accidents. We also need to understand what that appetite for violence--enabled by the energy density of the dynamite-based explosion--helped bring into the world. When the anarchists began dreaming of a society unfettered by institutional authority, there were no forensic detectives, no biometric databases of identity, no anti-terror agencies. Where official police forces did exist, they were usually in bed with urban crime syndicates and political machines; national and international investigatory bodies like Interpol or the FBI or the CIA were decades from being created. But in the end it turned out to be those institutions that triumphed over the stateless dream of the anarchists. In many key respects these techniques and organizations were prodded into being by the emerging threat of the infernal machines, like an immune response to an invading virus. The innovation of dynamite-driven political terrorism created a counterreaction from the forces of top-down authority, one of those stretches of history where some of the most powerful institutions in the world are shaped by the activities of marginal groups, working outside the dominant channels of power.

In this case, though, the legacy of the anarchist movement ultimately possessed a kind of tragic irony: the dream of smashing the state helping to give birth to a regime of state surveillance that would become nearly ubiquitous by the middle of the twentieth century.