Turn on the radio this week and a ghoulish voice from the bowels of the former World Trade Centre seeks to curdle your blood and chill your bones. It is yet another BBC trailer evoking the horror of the twin towers and the monster of evil, Osama bin Laden. The corporation is desperate to outdo other media outlets in their commemorations of the fifth anniversary of 9/11. They include movies by Oliver Stone and Paul Greengrass, and American and British 9/11 specials from stars such as Harvey Keitel and Kevin Costner called The Millionaire Widows, The Miracle of Staircase B, On Native Soil and numerous variants on twin towers. There are comic strips and videos and where-was-I-then memoirs. The weekend is to be wall-to-wall 9/11. Not glorifying terrorism? You must be joking.

The favourite line from the war on terror's military-industrial complex is that in 2001 Osama bin Laden "changed the rules of the game". (Forgotten is that he attacked the same target in 1993, his only error being one of civil engineering.) George Bush repeated the change thesis again on Wednesday in confirming his secret interrogation camps and excusing the five-year delay in bringing al-Qaida suspects to justice. Tony Blair cites the change with every curb on civil liberty. The "new" terrorism requires a new approach to public safety. The security industry cries amen.

Most of this is self-serving drivel. Nervous rulers have colluded with soldiers and businessmen throughout history to cite some ethnic or religious menace when needing more power and higher taxes. Political violence has become more promiscuous with suicide bombing and a consequent rise in kill rate per incident, but - as Matthew Carr shows in his book on terror, Unknown Soldiers - the change is one of degree.

Forty years after Alfred Nobel's invention of dynamite, Russian terrorists tried to pack a plane with the stuff and fly it into the tsar's palace. In 1883 Chicago-financed Fenians exploded bombs on the London underground, leading the Times to wonder if the tube could ever be safe. There has been little change in the preferred weapon of terror, the explosive device, or in the psychopathology of the bomber. The causes remain the same: separatism, and religious nationalism dressed up as holy war.

What has changed, grotesquely, is the aftershock. Terrorism is 10% bang and 90% an echo effect composed of media hysteria, political overkill and kneejerk executive action, usually retribution against some wider group treated as collectively responsible. This response has become 24-hour, seven-day-a-week amplification by the new politico-media complex, especially shrill where the dead are white people. It is this that puts global terror into the bang. While we take ever more extravagant steps to ward off the bangs, we do the opposite with the terrorist aftershock. We turn up its volume. We seem to wallow in fear.

Were I to take my life in my hands this weekend and visit Osama bin Laden's hideout in Wherever-istan, the interview would go something like this. I would ask how things have been for him since 9/11. His reply would be that he had worried at first that America would capitalise on the global revulsion, even among Muslims, and isolate him as a lone fanatic. He was already an "unwelcome guest" among the Afghans, and the Tajiks were out to kill him for the murder of their beloved leader, Ahmed Shah Massoud (which they may yet do). A little western cunning and he would have been in big trouble.

In the event Bin Laden need not have worried. He would agree, as did the CIA's al-Qaida analyst in Peter Taylor's recent documentary, that the Americans have done his job for him. They panicked. They drove the Taliban back into the mountains, restoring the latter's credibility in the Arab street and turning al-Qaida into heroes. They persecuted Muslims across America. They occupied Iraq and declared Iran a sworn enemy. They backed an Israeli war against Lebanon's Shias. Soon every tinpot Muslim malcontent was citing al-Qaida as his inspiration. Bin Laden's tiny organisation, which might have been starved of funds and friends in 2001, had become a worldwide jihadist phenomenon.

I would ask Bin Laden whether he had something special up his sleeve for the fifth anniversary. Why waste money, he would reply. The western media were obligingly re-enacting the destruction and the screaming, turning the base metal of violence into the gold of terror. They would replay the tapes and rerun the footage ad nauseam, and thus remind the world of his awesome power. Americans are more afraid of jihadists this year than last. In a Transatlantic Trends survey, the number of them describing international terrorism as an "extremely important threat" went up from 72% to 79%. As for European support for America's world leadership, that has plummeted from 64% in 2002 to 37% this year.

Bin Laden might boast that he had achieved terrorism's equivalent of an atomic chain reaction: a self-regenerating cycle of outrage and foreign-policy overkill, aided by anniversary journalism and fuelled by the grim scenarios of security lobbyists. He now had only to drop an occasional CD into the offices of al-Jazeera, and Washington and London quaked with fear. The authorities could be reduced to million-dollar hysterics by a phial of nail varnish, a copy of the Qur'an, or a dark-skinned person displaying a watch and a mobile phone.

A feature of democracy is freedom of information and speech. News of violence cannot be concealed since concealment fuels the climate of fear. The state should not censor news of terrorist incidents. As Milan Kundera asserted, "the struggle of man against power is the struggle of memory against forgetting". But there are ways of not forgetting. A feature of democracy is also to reject arrest without trial, reject the use of torture, and reject retaliatory violence against people or groups. Democracy can apparently sacrifice these legal principles to guard against the 10% of terrorism that is bang. Why not restrain the publicity that fuels the other 90%, the aftershock? The boundary between news and scaremongering may be hard to define. But so is any boundary between liberty and security. What is so sacred about publicising terror as against habeas corpus?

Conceding the kudos of state censorship to jihadists should be as unthinkable as conceding arrest without trial. That does not excuse the politico-media complex from any responsibility for caution, a sense of proportion and self-restraint. The gruelling re-enactment of the London bombings in July and this weekend's 9/11 horror-fest are not news. They exploit grief and horror, and in doing so give gratuitous publicity to Bin Laden and al-Qaida. Those personally affected by these outrages may have their own private memorials. But to hallow the events with repetitious publicity turns a squalid crime into a constantly revitalised political act. It grants the jihadists what they most crave, warrior status. It more than validates terrorism as a weapon of war, it glorifies it.

The best way to commemorate 9/11 is with silence. Instead, Bin Laden must be laughing.

simon.jenkins@theguardian.com