One of the more persistent myths that came out of the great wars of the last century involved telepathy, in particular the telepathic conveyance of bad news. Typically, the story features a woman who is going about her daily routine at home when she is inexplicably seized by the certainty that her man—whether son, husband, or brother—is in mortal danger. The story always ends the same way. Two or three days later the woman receives a telegram notifying her of the man’s death and placing the time at the precise moment when the conviction first chilled her being.

On September 11 the function of telepathic dread was for all intents and purposes served by the cell phone. Just before nine that day, the phone networks across America began to tremble with some of the most urgent and poignant messages in the history of mankind. “Honey, something terrible is happening. I don’t think I am going to make it.” “We can’t get out... the place is filling with smoke.” “I know we’re all going to die; there’s three of us who are going to do something about it.” These were the words of people in situations of unimaginable terror phoning home to speak of the catastrophe they faced and to give their final messages of love. They used GTE Airfones, office phones, and pay phones, but above all the ubiquitous cell phone. By the end of that day we understood that wireless had come of age and with it an immediacy that demanded as much from those who received the calls as it did from the men and women who made them.

Richard Makely, the father-in-law of Jeremy Glick, who died on Flight 93 near Pittsburgh, articulated the family’s ambivalence about his daughter Lyzbeth’s last conversation with her husband. “He had called from an [Airfone], not a cell phone,” Makely tells me. “I don’t know that at the time you were thankful you were talking to him. I think that initially there was shock that he indeed was involved in such a situation. So it was not a relief that we heard from him, but it was a combination of terror and sadness ... that he was there. I think, as the conversation went on, he and Lyz gathered a great deal of strength from each other in the discussion.”

No one was prepared for the proximity and cold certainty of this experience—of lines going dead in their hands, of signals dropping at the exact moment of extinction, and then instant confirmation of the unbelievable to be had by simply aiming the TV remote.

The telepathic and telegraphic messages of the past were in a sense conflated on September 11, and although thousands of people used their cell phones to bring news that they were safe, the knowledge of these 20 or so calls from the planes and countless others from the World Trade Center greatly added to the national anguish. This is to say nothing of the unendurable pain suffered by those who were reassured by family members in the towers who never made it home that night, nor any other. It was a shocking novelty, and that was because we had never fully appreciated the potential of the little device we carry in our pockets and purses. We swore by its convenience, praised its versatility, and resented its intrusiveness, but we did not for one moment imagine that it gave us the power to channel one person’s consciousness into another’s a few seconds before death.

And yet the reflex was there, the instinct which made many of the Americans who own 125 million subscribed cell phones hit the speed-dial keys that would put them in touch with their loved ones. When the planes struck, there was an unprecedented surge of calls in the New York area. As people streamed from the buildings northward through Manhattan, the only thing they wanted to do was to make that call. Both Verizon Wireless and AT&T Wireless experienced record traffic levels, with Verizon reporting twice as many calls during this period as it had ever logged before. These are figures for the calls handled, not for the ones that didn’t get through, whether because of the antennae on and around the World Trade Center’s towers being destroyed or the remnants of the overloaded system crashing. Thousands upon thousands of calls were unsuccessful for the basic reason that each relatively low-powered cellular antenna can handle only around 100 calls at a time. The wireless carriers recovered most of the service by the evening of September 11 after moving in mobile antennae known as “COWs” and directing traffic away from the World Trade Center area, but the limitations of a system which faints with exhaustion when it is most needed must surely be plain.

Even so, the cell dependency is now firmly established. In the days after the attacks, Americans bought a lot of train tickets, guns, and cell phones. The last two are held to be essential emergency equipment, although it takes only a nanosecond to realize that the phone is a great deal more useful than a gun if you’re caught in a collapsed building, stranded in the mountains, or lost in fog offshore and need to guide rescuers to your position. Victims did make calls from the rubble of the World Trade Center, a circumstance which was not lost on the hundreds of workers who were evacuated from the Prudential Tower in Boston when fire broke out on the 32nd floor six days after the attacks. In a drill which had been instilled by the example of New York, they grabbed their cell phones and headed for the stairways.

For a long time in America the cellular phone seemed like a rich man’s toy, the kind of thing only a gangster or Gordon Gekko would be seen with. It had obvious benefits for drug dealers, adulterers, and kids with the time to indulge in the textmessaging craze, but there seemed something mildly exhibitionistic about the instrument, which perhaps accounts for the pleasure we took when the Clintonesque character Jack Stanton in Primary Colors hurled a phone from the window of a speeding S.U.V. Today, when the phone is endowed with lifesaving and faculty-extending capabilities, such an act would seem pure folly.

Outside America, where telecommunications infrastructures are less reliable and sometimes nonexistent, people got the point about wireless a lot sooner. In the Middle East, for instance, they realized that all its obvious advantages were matched by an equal and opposite potential for destruction. While messages of pity and relief flashed between cells in America, there was an altogether different reaction among some Palestinians. Three days after the tragedy, the London Times printed a picture of a Nokia cell phone in close-up taken by the Lebanese photographer Marwan Naamani. Shown on the phone’s display was a tiny graphic of a jet about to crash into a representation of the World Trade Center. The Arabic caption below translates as “It hit and did not miss.” The message was sent by a Palestinian living in Syria to a friend in Switzerland and then onward to Egypt, where Naamani took the picture.

As people streamed from the buildings northward through Manhattan, the only thing they wanted to do was to make that call.

It is perhaps no coincidence that one of the Arab terrorists on the planes encouraged the passengers to phone home and “tell them you are abqiut to die,” according to the London Times. He knew about phones, knew that an airplane flying over the East Coast would travel through the “footprint” of scores of different antennae, and maybe he thought he’d have a little fun on the brink of hell. At any rate, that same man, so steeped in the lore of the Islamic jihad against Israel and its Western backers, would almost certainly have been aware of the story of Yahya Ayyash, a Palestinian bombmaker and member of the Islamicextremist group Hamas. Ayyash was assassinated by a phone.

On the morning of January 5, 1996, Ayyash—nicknamed “the Engineer”—was hiding out in the maze of slum dwellings in Beit Laahiya, at the northern end of the Gaza Strip. He had been told to expect a call. When his cell phone rang, an associate named Osama Hamad answered; Ayyash’s father was on the line. Hamad handed the phone to Ayyash, who began to speak, brushing aside his father’s worries about Israeli surveillance. “I told him that we don’t want to talk on this phone,” said his father at the time. “But he said we could talk. When I told him ‘No’ again, he asked, ‘How are you?’” At that moment nearly two ounces of high explosive packed into the phone detonated. Half of Ayyash’s head was blown off, together with his hand. He died instantly, giving the likely architects of this operation, Israel’s Shin Bet security service, cause to celebrate. The Engineer had been one of their wiliest foes, and the plan to insinuate the phone into Ayyash’s household and set it off while he was using it required exceptional intelligence work. The phone belonged to his associate Hamad, and it is thought that it was lethally adapted during the period when Hamad lent it to an uncle of his, who, it turned out, had connections with the Israeli military. What is certain is that once the phone was back in Hamad’s possession, his uncle rang on the landline to the house and told him to expect a call on the cell phone. Very soon afterward Israeli agents blocked the landline so that all calls would have to go through the cell. At the same time, they must have been monitoring the cell phone, because they had to be sure that it was Ayyash speaking before they detonated the explosives. When they heard his voice they triggered the detonator by means of a radio signal which is believed to have come from a plane flying overhead. By any standards, it was coordination of a very high order indeed.

On both sides of the dirty little war between the Palestinian extremists and the Israeli security forces, the phone has been deployed with demonic ingenuity as a weapon of terror. Since September of last year, some 60 Palestinians suspected of being militants reportedly have been assassinated by doctored cell phones, gunmen, car headrests packed with explosive, or laser-guided missiles launched from helicopters. In July of this year Palestinians belonging to a radical Marxist group replied with two car bombs planted in the Israeli town of Yehud, near Tel Aviv’s Ben-Gurion Airport. Both were detonated by cell phones. Two weeks later a black plastic bag spotted by the roadside in the Jordan Valley was found attached to a cell phone. Inside the bag was a 160-mm. tank shell.

The phone has become the preferred bomb trigger because it is a relatively simple procedure to wire a detonator so that when the ringer is activated the detonator fires. The beauty of this technique for the terrorist is that the extended life of the now common lithium battery allows him, in theory, to fly to the other side of the world and set off his bomb with a call from a distant pay phone. In the case of a roadside bomb, which usually targets passing police or military vehicles, it is essential for the terrorist to keep the road in view so he can make the call at the right moment.

The West has been so absorbed by the vertiginous growth of the Web that we have failed to grasp the more menacing aspects of wireless telephony. True, we fretted about people using the phone while driving or answering calls at inappropriate moments. And some began to take notice of one study linking brain cancer and cell phones, which, according to London’s Daily Telegraph, now suggests that the use of mobile phones over a 10-year period increases the risk of brain tumors by 26 percent. (It rises to over 77 percent for more than a decade’s use.) There were also issues that we ignored, for instance the one concerning privacy.

When in use, a cell phone sends a constant stream of data to the carrier’s antennae, giving both its position and its electronic serial number (ESN). This information is retained by the carrier for billing purposes, but the records can be immensely useful in tracing the movements of a person over a period of months. This is why the phone records of Mohamed Atta, who is believed to have been flying the first plane to hit the World Trade Center, are so important. They provide a clear picture of his movements and also list the hundreds of calls he made. In other words, intelligence agencies will be able to gradually lay bare a web of terrorist contacts simply by searching the memory databases of phone companies. Normally a terrorist would never make such an obvious mistake, but Atta seems to have been oblivious to or nonchalant about the digital trail he was leaving behind him.

One of the Arab terrorists on the planes encouraged the passengers to phone home and "tell them you are about to die.”

Potentially, a phone can be located in real time. Even when it is switched on but not in use, it periodically sends a signal to the nearest antennae. In open country the triangulation made on the signal of a phone is accurate only to within 5 to 10 miles, but in cities it is theoretically possible to get a fix within 500 feet, which is why in the days after the attack on the World Trade Center the carriers contacted people in the Lower Manhattan area who had merely switched on their phones. The carriers were monitoring the phones to see if the signals were coming from the rubble of the World Trade Center and, if so, if people needed help.

The accuracy of this location-finding capability by cell phone will be greatly increased in the future because the Federal Communications Commission has regulat_ ed that carriers roll out a program called Enhanced 911 by December 2005. It has yet to be decided by the carriers whether they will use G. PS.—the satellite-based Global Positioning System— or new network equipment which will refine triangulation technology, but either way the potential to invade people’s privacy is enormous. In essence, all phone users will be walking around with a beacon that is sending out a signal saying, “It’s me, John Doe, and I’m 200 yards from Yankee Stadium, right by the hot-dog stand.”

errorists and criminals were way ahead of the game on this, too. For years they have known that to use one particular phone is to invite surveillance and even death. The U.S. and U.K. founded a global eavesdropping network called Echelon, which is named after a highly sophisticated search engine that sorts through billions of bits of intercepted data for key phrases, names, and numbers. Originally designed to listen in on the military communications of the Eastern bloc, Echelon has had to adapt as the planet’s ether becomes increasingly saturated with various kinds of electronic signals, many of them encrypted. The National Security Agency (N.S.A.) at Fort Meade, Maryland, and British Government Communications Headquarters (GCHQ) in Cheltenham task their listening equipment, which includes some of the world’s largest computers, to search for a particular cell phone. Linked to speech-identifying technology, Echelon is highly effective in tracking a target, which is why terrorists stick to landlines or use a cell phone once and throw it away.

The other reason for not using a cell phone is that the cellular or satellite phone is a potential homing device for a missile. James Bamford, whose book Body of Secrets is a standard authority on electronic espionage and the Echelon network, says, “Cell phones have been used as guiding mechanisms for missiles.” Bamford even suggests that the Israelis have used them for that purpose. “In other words, it [the cell phone] sends out a signal, and what a guided missile does is follow a signal right to where the transmitter is.” The Russians used a variant of this technology when they killed the Chechen leader Dzhokhar Dudayev in April 1996 with an air-to-surface missile that homed in on his satellite phone.

As with the Ayyash case, the operation entailed a good deal of covert manipulation, which, according to the intelligence periodical Covert Action Quarterly, may even have involved President Boris Yeltsin. During the spring of ’96, Yeltsin offered an unexpectedly generous deal to the Chechens, who were and still are seeking to secede from the Russian Federation to found an independent Islamic state. He proposed as mediator King Hassan II of Morocco, which meant that Dudayev would have to call Hassan and possibly other advisers before responding. The only way he could do this was by using the satellite phone the Russian security forces knew he had. On four occasions in the first three months of 1996, the Russians had tried to use airborne direction-finding equipment to lock onto his signal, but they had always been frustrated by the brevity of Dudayev’s communications. This time they hoped he would use the phone long enough for them to get a fix.

On April 21, at eight P.M. local time, Dudayev left his house in Gekhi-Chu, about 20 miles southwest of Grozny, and made two calls in open air. He spoke first with King Hassan II, then called the Chechen intermediary in Moscow, Konstantin Borovoi. He conducted part of the conversation with Borovoi in thinly coded hints which seemed to warn him of an imminent bombing at the Interior Ministry, next door to where he worked. According to Covert Action Quarterly, Dudayev said, “Soon, it could be very hot in Moscow. Do you live in the Center? You should probably move out for the time being.”

Dudayev’s last words before the line went dead were “Russia must regret what it is doing,” a remark which gave what was happening in the evening sky above him a grim irony. Seconds later a Russian Sukhoi Su-25 jet received the coordinates of the signal from Dudayev’s phone and launched two laser-guided missiles. One exploded a few feet away from Dudayev. He was hit by shrapnel in the head and died in the arms of a bodyguard soon afterward.

At the time of the assassination there were suspicions that the Russians had been given help in tracking the satellite phone by the N.S.A., which could easily have retasked its spy satellites over the Middle East to sweep the sky above Chechnya. Wayne Madsen of Covert Action Quarterly argued that since the N.S.A. had already been sharing with the Russians intelligence gathered by eavesdropping on cellular networks, it would be no great leap for the agency to help track down another kind of mobile phone, in this case the satellite phone of a man who, in the wake of the constant threat of Chechen action in the center of Moscow, may have been regarded as just another Muslim terrorist. That we know the contents of this exchange between Dudayev and his associate in Moscow underscores just how intense the surveillance was of Dudayev’s phone.

Intelligence agencies will be able to gradually lay bare a web of terrorist contacts by searching the memory databases of phone companies.

A similar operation was planned against Osama bin Laden in August 1998, when the U.S. hit back after embassy bombings in Dar es Salaam and Nairobi. Intelligence services knew that bin Laden used an INMARSAT phone, and it is believed that, of the 60 or so cruise missiles fired, the U.S. targeted at least one on the phone’s signal. Reports now suggest that bin Laden had left a meeting of between 200 and 300 members of the al-Qaeda group just an hour before the missile strike, which is believed to have killed up to 30 members of his organization, and that he has since cut back on the use of electronic communications. After the Dudayev assassination, bin Laden must have been wary of using his phone; indeed he had been alerted to the possibility of U.S. attacks by the sudden withdrawal of U.S. Embassy staff from Islamabad, the capital of neighboring Pakistan. If he needed any confirmation that he was being stalked by N.S.A. satellites, it was helpfully provided by a leak in the media a year later which confirmed that the N.S.A. and GCHQ had traced his phone. It is hardly surprising that bin Laden became much harder to track. Besides, his brother Sheikh Hasan bin Laden was a director of Iridium L.L.C., a company which now runs a global satellite network based on 66 communications satellites. In fact, the Saudi Binladin Group, a company belonging to bin Laden’s Saudi family, had invested heavily in the Chinese Long March rockets which launched four of the satellites into low orbit. So we can be sure that one thing America’s most wanted man knows about is cell phones and satellites.

In the wake of bin Laden’s onslaught on America, it is hardly necessary to stress the extraordinary role played by mobile phones in the day’s events. Those people left behind, a dial tone sounding in their ears, the words of their loved ones playing over and over in their heads, certainly need no persuasion. Wireless telephony is embedded in the history of September 11, and in one shining instance the cell phone had a direct bearing on the outcome of the day. Without the calls from United Flight 93, during which passengers learned about the attacks on the World Trade Center, it seems certain they would not have fought back and thwarted the finale of the terrorists’ plan. Where the military and intelligence responses of that day failed, the cell phone triumphed.