What does the Taliban’s return mean for al-Qaida in Afghanistan?

UK defence secretary is worried that al-Qaida will probably come back' - but it is already there

• Taliban enter Kabul - live updates

As the Taliban prepare to rule Afghanistan after sweeping across the country in less than a week, an obvious question is what does this mean for the future of al-Qaida and other extremist Islamist groups committed to waging a global jihad.

There is no doubt that the astonishing rapidity of the Taliban's victory will deliver a tremendous boost to Islamist extremists everywhere - whether al-Qaida, Islamic State, fighters in Mozambique or Syria, or jihadi fanboys in bedsits in Birmingham or Manila.