Reporter Peter Taylor has spent five years since the events of 11 September, 2001, investigating al-Qaeda in Britain and around the world.
AL-QAEDA: TIME TO TALK?
In the first of two special investigations, Peter Taylor concludes that Iraq has become the dominant radicalising and recruiting force for many Muslims and that British support for US foreign policy has made Britain a prime target.
With the so-called "War on Terror" far from won, and August's chaos at UK airports, is it time to consider a new approach?
To try and end the violence, is it time to engage with al-Qaeda?
AL QAEDA: TURNING THE TERRORISTS
The second investigation, Turning The Terrorists, looks at how South East Asia - long al-Qaeda's recruiting, training and planning base - has been successful in fighting the international terrorist threat.
The region became al-Qaeda's new Afghanistan, attracting jihadis from all over the world, including the UK.
The strategy is to hit the terrorists hard but also to persuade them to change sides and help the authorities defeat their former comrades.
The result has been the rolling up of hundreds of members of Jemaah Islamiya (JI), the al-Qaeda-linked terrorist organisation responsible for the Bali bombings.
The scoop of the programme is the unprecedented access to and interview with Nasir Abbas, a former senior JI commander who changed sides to become an Islamist "supergrass", and now a key weapon in Indonesia's war against the terrorists.
Abbas trained many of those behind the 2002 Bali bomb and is the brother-in-law of its key planner - although Abbas profoundly disagrees with the operation that killed so many civilians.
He also trained many leading terrorists in the Philippines. It was there, too, that he met jihadis from overseas, including the UK.
Intelligence agencies from overseas are now beating a path to his door.
Today, he not only provides the authorities with intelligence on his former comrades, but also talks to them after they have been arrested and tries to convince them that they followed the wrong path... in the hope that they will change sides too.