John O'Neill

John P. O'Neill, intelligence officer: born Atlantic City, New Jersey 1951; died New York 11 September 2001.

From the terrorists' viewpoint, the events of 11 September in Lower Manhattan and at the Pentagon in Washington were an unqualified success. But even the perpetrators themselves cannot have imagined a smaller bonus for their cause: the death in the collapse of the World Trade Centre towers of John O'Neill, one of America's foremost anti-terror specialists, and pursuer of Osama bin Laden and his al-Qaeda network for the better part of a decade.

Until the end of the previous month O'Neill had been chief of the FBI's counter-terrorist division. It was only his second day on his new job as the Trade Centre's chief of security when the first hijacked jetliner slammed into the north tower. O'Neill was in his 34th floor office at the time. Having left the building and informed his family he was fine, he went back in to help the search for survivors. He was killed an hour later when the building collapsed.

From his schooldays, John O'Neill wanted to be a "fed". He started his career with the bureau in 1970 as a clerk, weeks after leaving high school. After earning a Bachelor of Science degree, and then a master's in forensic science at George Washington University in Washington, he started work full-time in 1976. After attachments at FBI field offices in Baltimore, Chicago and Washington he was put in charge of the group at the bureau investigating the spate of attacks at abortion clinics in the early 1990s. The move to counter-terrorism pure and simple was natural.

Over the last few years O'Neill was involved in all of America's biggest terrorist cases: from the investigation of Islamic extremists' initial attack on the World Trade Centre in 1993, in which six people died, to the 1995 Oklahoma City bombing; from the long and ultimately inconclusive probe into the mystery of TWA flight 800 to the successive attacks on US bases in Saudi Arabia in 1995 and 1996, the US embassy bombings in Africa in 1998, and last year's attack on the destroyer USS Cole in the port of Aden, Yemen. With the exception of TWA 800 (with which no terrorist connection was ever proven) and Olkahoma City (which turned out to be the work of the home-grown extremist Timothy McVeigh), O'Neill established links between every incident and the Saudi-born bin Laden.

Even among his peers, O'Neill stood out; not just for for his height (6ft 2in) and stylish dress, but for his obsession with his work, his determination and meticulous attention to detail. He absorbed information like a sponge, and worked without respite – often in a succession of 18-hour days which he bore without complaint. Of him, the head of Scotland Yard's anti-terrorist branch, Deputy Assistant Commissioner Alan Fry, once remarked, "I wouldn't want to be the terrorist he was hunting. I've seen John O'Neill move heaven and earth."

Inevitably, however, that relentlessness attracted controversy – especially when his work brought him into contact with foreign countries and with America's own diplomats, unaccustomed to his steamrollering, take-no-prisoners style. The investigations in Saudi Arabia were notably unproductive; a clash of cultures in which the FBI could not understand the political sensitivities of the Saudi government.

It was a similar story in Yemen, when the US ambassador, Barbara Bodine, ultimately refused to let O'Neill back into the country. She claimed that the size of the FBI team he insisted on bringing for the USS Cole investigation, and his demand that his men be allowed to carry automatic weapons, would create intolerable friction with the local authorities.

The coup de grâce for his FBI career however appears to have been an internal investigation launched this spring into a missing briefcase containing classified information which O'Neill left in a conference room in Tampa, Florida, last year. The briefcase contained sensitive security documents, including details of every major counter-terrorism programme in New York. Shortly afterwards, he resigned, and took up the job at the World Trade Centre.

Events however have tragically vindicated his deeper judgement. In 1997 he delivered a speech to an anti-terrorism conference in which he sketched out his fears of "either sustained attacks or very large attacks" in the US itself that would cause heavy casualties. O'Neill singled out Islamic extremist groups as a particular menace. Almost all of them had a presence in the US:

They are heavily involved in recruiting and fund-raising activity . . . They talk across group lines . . . You tend to figure out who they may be associated with and, all of a sudden, they're talking to all of the different groups at a conference where they are all bound again by the Jihad, by their religious beliefs and extremism. And almost all of the groups today, if they chose to, have the ability to strike us here in the United States.

That prophecy – and its uncanny awareness of the modus operandi of this month's hijackers and their accomplices – came true on 11 September 2001, in the disaster which cost John O'Neill his life.

Rupert Cornwell