If the first casualty of war is truth, the first casualty of the war on terror has been grammar. How is it possible to go to war on a common noun – or on a state of mind rather than a state? Terrorism – broadly defined as politically motivated killing of civilians – has forever been a tactic of cruel men wanting to achieve or maintain power. Among the first to protest was the playwright Euripides in 415 BCE, who shamed his countrymen for their slaughter of boys and enslavement of women after the siege of Melos: the howling inhumanity staged in The Trojan Women has echoed through Guernica and Dresden, Srebrenitsa and Darfur, New York on 9/11 and London on 7/7. But what is new about suicide bombers? Guy Fawkes was caught ‘bang to rights’ in the basement of parliament with matches and a taper leading to the barrels of gunpowder way back in 1605. Later that century, when the Restoration brought Hugh Peters (the founder of Harvard) and Sir Henry Vane (a former governor of Massachusetts) to trial at the Old Bailey, the prosecution described them, in effect, as international terrorists groomed by the fundamentalist Puritan preachers of New England to return and persuade Cromwell to execute Charles I – an event which spread terror through the crowned heads of Europe. In the 1790s, it was fear of the export from France of violent Jacobinism that led Pitt to gag the press and suspend habeas corpus. In short, we have been here before.

The first virtue of this account of terror throughout the ages is to make that very point. Terror has been a tactic variously of Fenians, Narodniks, weathermen, Malaysian guerrillas and IRA bombers, before the explosives of Islamic fundamentalists began to trouble the Western world. The motive has always been political or religious or a combination of both and the strategic objective has been to provoke the authorities into responses so repressive that they will rally supporters who would not otherwise have sympathised with their cause. An overriding lesson to be drawn from all this history of terrorist alarums and excursions is that society must not overreact: reducing human rights is not only a form of surrender but gives the perpetrators exactly what they want. Their ‘propaganda by deed’ theory – that ideology is better spread by inspiration from actions rather than from words – works because of the long-term consequence of panicked official repression, as in deploying torture or internment, or holding unfair trials. History shows that smart counter-terrorism eschews severe incursions on civil liberties and treats atrocities as the most serious of gangster crimes, to be combated by better intelligence and more effective police work, and by building up international co-operation between law enforcement agencies.

Another virtue of this volume is that many of its chapters remind us that terror tactics are not confined to revolutionaries. Too often in history terror has been the weapon of governments or dictators, harnessing state power to oppress and intimidate the people. The English regicides believed that executing the king was an act of justice, rather than ‘cruel necessity’ or general deterrence: one reason why their republican revolution did not descend into the incontinent blood-letting of Thermidor was that they did not abandon their respect for forms of restraint (Magna Carta, habeas corpus, public trial before independent judges) that they had fought to uphold against the king. But come the French Revolution, we have the example of a makeshift legal machine (denunciation, followed by show trial in a ‘revolutionary tribunal’ and then a march to the gallows) that develops an unstoppable momentum. Injustice, indeed, becomes the prime instrument of state terror, operated by lawyers like Fouquier-Tinville and Andrei Vyshinsky, who see themselves as merely doing their duty. Stalin’s show trials convinced the willing dupes in the West through the use of fig-leaf legal formalities that hid the mental and physical tortures that produced the confessions. Meanwhile, trial by ‘troika’ in the provinces became a means of despatching millions of potential rather than actual fifth columnists. In such times, the very prospect of dissent or criticism instils fear in the paranoid minds of regime rulers and their obedient prosecutors: terror feeds off itself, in an increasingly viscous cycle.

The techniques of terror, whether perpetrated by the State or by revolutionary groups (terror from above or terror from below), are invariably cruel – unbearably so, whatever the justification. Pinochet’s belief that the fear generated by his torture chambers was necessary to the national interest of Chile was as ‘idealistic’ as the IRA’s certitude that its bombs were in the national interest of a united Ireland. Those who murder and torture for political or religious objectives are incapable of compassion or of rational persuasion: terrorists rarely apologise, and states which do deals with them to achieve short-term solutions in a hostage crisis or a hijacking will merely equip them to strike again. Whether they get away with their crimes is generally a matter of political expediency. Colonel Gaddafi, the worst man left in the world, who was until recently chief sponsor of international terrorism, is now a valued friend to the West. He is a leopard who only changed his spots because of his own fear of al-Qa’ida: Islamic fundamentalists cannot abide the apostasy of government by his Green Book. Some of those he funded, like IRA killers in Northern Ireland, have been amnestied by ‘peace processes’ although the relatives of death squad victims are beginning to call for retribution. An emerging international criminal law questions whether amnesties can ever be valid for crimes against humanity – and terrorist outrages, when part of widespread and systematic attacks on civilians, fall within that category.

Cruel and amoral though they be, terrorists are nonetheless human and therefore predictable – as John Horgan explains in the final chapter, men of whom martyrs can be made have always had predisposing factors, notably experience of victimisation and identification with the cause of a victimised community. The real challenge for counter-terrorism is to come to imaginative grips with that victimhood and even to remove its cause – a challenge most notable today in the case of Palestine. The reason for our failure of empathy in relation to Islamic extremists may be that we regard them as other than human. I was in London on 7/7, where the multi-national denizens of this city, most of them unborn at the time of the Blitz, showed the same stoicism. They were unflappable, stiff upper-lipped amidst the carnage of broken buses and burned-out tube trains. Yet a few weeks later, on 21/7 when the attacks failed, the city almost went to pieces: police were jumpy, there was panic at tube stations; nobody dared tackle escaping bombers as they ran up the escalators and a police hit squad jumped an innocent man and pumped bullets into him – seven of them. The movie War of the Worlds was showing at the time, and it struck me that we were beginning to treat terrorist suspects in the way Tom Cruise treated the aliens – as sub-human, virtually indestructible (hence the 7 bullets) and remorselessly advancing. 21/7 was a bad day, notwithstanding the lack of casualties: there was a pervading sense of panic, as if the city realised for the first time that the war on terror would now be endless. This book may help the realisation that it has simply never ended.

As with most good history updates, there are some surprises and some calls for re-evaluation. The Gestapo, for example, was not all that bad, as Nathan Stoltzfus discovers, at least if you were amongst the majority of law abiding Aryans. The Cheka, on the other hand, was not a necessary response to White Russian counter-Revolution, but a repressive agency planned by Dzerzhinskii before the civil war even started ‘to conquer the enemy even if its sword does by chance sometimes fall on the heads of the innocent’. It is this insouciance towards the prospect of killing civilians and children, this merciless wish to break more eggs than necessary to make omelettes, which characterises the terrorist through the ages. Lenin’s order to exterminate the children of the Tsar (together with their valet, cook, parlour maid and doctor) paralleled Odysseus at Troy convincing the Greek commanders of the need to dash out the brains of Hector’s infant son.

Does cruelty matter if it is to advance a cause believed to be just? Maybe Allende would have prevailed had he set up torture chambers for his enemies first, but then he would have survived as no better than Pinochet. The intentional killing or torture of civilians can never be excused, whether it comes as a deliberate act of class malice (e.g. the Red Brigades and the tedious Baader-Meinhofs) or because they represent a ‘guilty’ race (of Israelis or Americans, or American allies) or simply because they are people (including Muslims) sitting on a London bus and happy to live and work in a country that does not observe Sharia law.

In war, the slaughter of civilians is a war crime, contrary to the Geneva Conventions. In peace it is a crime against humanity that must be investigated and punished in the ordinary way, rather than a state of emergency warranting general loss of civilian liberties. Michael Davis and Paul Pickering, in their essays on government reactions to the French Revolution and to the Chartists, remind us just how easy it is to scaremonger during a moral panic over terrorism that can lead parliament to pass ‘gagging acts’ suspend habeas corpus and conduct staged trials in front of juries too frightened to acquit.

The impact of 9/11 and 7/7 and the mass murders in Bali discos and Madrid trains and Moscow theatres and Beslin schools has been to create a climate where terrorism is an ever-present possibility. The government reaction, in the US, the UK and Australia in particular (the three nations most anxious to crusade in Iraq) has been to cut back habeas corpus as a protection for aliens and for terrorist suspects (they are held in Britain for up to 28 days – the government favours 90). These and other departures from human rights rules and norms are excused because there is a ‘state of emergency’, but this excuse only applies to situations that ‘threaten the life of the nation’. Fundamentalist Islamic terrorism threatens to take lives, from time to time, in Western nations, but not to impair state functions or cause more than temporary inconvenience. Similarly, attempts to stop radical preachers by inventing new hate speech crimes are doomed to failure. It is an offence in most jurisdictions to incite violence or incite others to commit murder or to bring about civilian deaths recklessly: not even the first amendment to the US Constitution protects those who shout ‘Fire!’ in crowded theatres. But criminal restrictions on speech create martyrs or drive incendiary mullahs underground: at one stage the UK proposed a law against ‘glorifying terrorism’ so wide-ranging it would have banned a sympathetic biography of Robespierre.

There is a sense in which terrorism, in Walter Laquer’s words, is ‘the weapon of the weak’, but suicide bombing is usually a weapon used against the weak, those ordinary citizens blown to pieces whilst going to work in trains or buses or relaxing in crowded cafes or discotheques. What is owed to these victims is not a ‘counter terrorism’ in which uniformed men in tanks and planes inflict the equivalent grief on people in the community which the terrorists wish to make stronger: that simply locks the vicious cycle. Courage is required to counter the fear which terrorism spreads, and that courage comes from belief in the value of liberal democracy and – most difficult this – a willingness to address the real grievances that terrorists so cruelly and criminally protest about. It does the dead a disservice to call their killers ‘evil’ or ‘cowards’ or to otherwise dehumanise them by perceiving them as aliens. The point surely is that they are fellow human beings and that their actions morally diminish us all – to a level that our own reactions must strive to rise above.