When all the heroics of the US raid on Osama bin Laden’s compound and the intelligence operation which preceded it have been analysed, one fact stands out – that the al-Qaeda leader had been hiding, probably for years, in Pakistan barely 50 kilometres from the capital, Islamabad.

Far from living in a cave, or being sheltered by tribal groups in Afghanistan or in the border area in Pakistan, bin Laden was living in a big, bustling city with a population of about 1m people.

President Barack Obama underlined the deepening disillusionment with Pakistan by his pointed decision not to inform its government about the raid beforehand.

Just as the audacious attack on the US orchestrated and financed by bin Laden had ramifications that even the Saudi-born terrorist could not have fathomed, the fallout from his death is also impossible to predict.

The 9/11 attacks triggered the invasion of Afghanistan, where US-led military forces remained bogged down nearly ten years later, and were also pivotal in pushing George W. Bush into a costly war in Iraq.

The revelation that bin Laden was effectively hiding in plain sight, not in the lawless tribal areas near Afghanistan but close to Islamabad, will also deepen the crisis in Washington’s ties with Pakistan.

Al-Qaeda is a vastly different, and probably weaker, organisation from the time of the attacks. It has splintered into various regionally-based cells, in places like Yemen and Somalia and in parts of southeast Asia, and has not been able to mount any significant, successful attack inside the US since 9/11.

But the US and its allies, and also Arab countries, fear a backlash in the wake of bin Laden’s death, perhaps from cells which have been primed to respond to such an event, or by people who could be radicalised by it.

Ahead of the announcement by Mr Obama, the ability of bin Laden even in death to galvanise the US national security establishment was on display, with military bases around the world being put on a top security alert and the state department issuing a travel warning.

The symbolic significance of bin Laden’s death cannot be overestimated, especially in the US.

“As the al-Qaeda leader, his authority was respected and he maintained the body’s cohesion,” said a senior administration official.

The failure of the US to catch or kill bin Laden through the remainder of the Bush presidency hung like a shadow over his administration.

For Mr Obama, the possibility of a domestic terrorist attack by al-Qaeda and its affiliates contained not only national security implications but also a political threat.

But the US president acknowledged in his speech that the death of bin Laden did not mean the end of al-Qaeda, or terrorist threats against the US and its allies.

“There is no doubt that al-Qaeda will continue to pursue attacks against us,” he said.

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