Kim Sengupta: Why Bush's 'dead or alive' posse haven't got their man

The rumour spread through Kabul with astonishing speed. Osama bin Laden had been injured and captured, or actually killed. That was Kabul in June, as the Afghan war became increasingly violent with wave after wave of suicide bombings. But the mention of Bin Laden on the journalistic, military and diplomatic grapevine had an electrifying effect, vividly illustrating the mystique that surrounds the man who has come to epitomise terrorism on a spectacular scale for the West.

The tale at the time was that a top secret American and British unit had tracked down the founder of al-Qa'ida in the Wakkan Corridor, on the northern edge of Pakistan. Like previous reports it turned out to be baseless. Seven years after the September 11 attacks on America, Bin Laden remains as elusive as ever.

The Americans have recently started devoting greater resources to the hunt for the man on the top of their most wanted list. George Bush, it seems, wants the man he vowed to capture "dead or alive" before he leaves office. There have also been reports of Bin Laden at various points in Pakistan's border region, some of them placing him in north Waziristan where the "Pakistani Taliban" is the de facto ruler after a series of deals with the government in Islamabad. There have also been reports that the US came close to killing Ayman al-Zawahiri, deputy leader of al-Qa'ida, in air strikes.

But US and British commanders privately admit they are seriously hampered by a lack of intelligence about the whereabouts of the al-Qa'ida leadership. They cannot depend on the ISI, the Pakistani secret service, which is widely perceived to back Islamist terrorists.

The failure of the hunt has added to the frustration at lost opportunities in the past. After the fall of the Taliban in 2001, Bin Laden was holed up in Tora Bora with American and Afghan troops attempting to box him in. But the refusal of Donald Rumsfeld, the US Defence Secretary, to deploy additional troops allowed him and his chief lieutenants to escape into Pakistan.

In March 2003, there was credible information that Bin Laden and many of those closest to him were in the Pech Valley in Kunar, the teams hunting al-Qa'ida called for an immediate operation in the area. But by then Bush and Tony Blair had moved the "war on terror" to Iraq and Saddam Hussein was the top prize, not Bin Laden.

Early in 2006, the Saudi dissident made several audiotaped statements, and another appeared on a website in July 2007, but it was not clear from the content when it had been recorded. No videotaped recordings of him have been released since October 2004.

In July 2006, the CIA unit tasked with hunting Bin Laden, codenamed Alec Station, was closed. Iraq was still the main focus of Washington's attention and it was felt resources were needed there.

The task of finding Bin Laden, said a senior security official, is now more difficult than ever. "Since the elections in Pakistan we have got to be more careful about carrying out air raids across the border, although if we have a sniff of locating Bin Laden there'll be no compunction about ordering a strike, but I wouldn't bet on when that will be."