Twelve and a half years after 9/11, al-Qa’ida-type organisations control an area the size of Britain in western Iraq and eastern Syria. Include Afghanistan, Libya and Somalia and the territory they rule is larger in size than the UK. What is so extraordinary – and blameworthy – is that this vast expansion of jihadist groups comes even as the US, Britain and others are waging a “war on terror”. In the name of such a struggle, great sums have been spent; wars have been fought in Iraq and Afghanistan; civil rights have been curtailed; and torture, rendition, detention without trial and domestic espionage have been justified. But attempts to eliminate the supposed enemy have wholly failed.

It is to consider the roots of this failure that The Independent published a five-part investigation by our distinguished correspondent Patrick Cockburn this week. The aim of the series is to show the extent to which jihadist organisations identical in ideology and methods to Osama bin Laden’s al-Qa’ida have survived, flourished and are now stronger than ever.

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The US has spent billions of dollars to counter the threat of global terror and succeeded in killing Osama bin Laden three years ago. Yet today, al-Qa'ida-type groups are numerous and powerful.

Saudi Arabia has been perhaps the jihadists’ greatest ally – but will the Kingdom be forced to change tack in the face of American impatience and anarchy in Syria?

On the growing influence of Isis, formerly al-Qa’ida’s force in Iraq, which dominates Sunni areas and is wreaking havoc among the Shia majority

How extremist Islamists have turned the uprising against President Assad into a sectarian war and forced out seculars.

How Sunni fundamentalist groups are successfully winning recruits through well-funded internet propaganda.