Michael Fallon: 'Fight against extremism takes time'

The Queen and many veterans are attending a service at St Paul's Cathedral to commemorate the end of British involvement in the war in Afghanistan.

UK forces were part of a US-led coalition which invaded Afghanistan and toppled the ruling Taliban in 2001, following the 9/11 attacks in the US.

At the peak of the 13-year campaign the UK military had 9,500 troops and 137 bases in Helmand Province.

Speaking before the service, the Defence Secretary Michael Fallon said Islamist extremism was taking more forms and that the Afghanistan campaign had shown that operations against extremism took time.