9/11 - 20 years on

Days after the US withdrawal from Afghanistan comes the anniversary of the terrorist attack that sparked the invasion in 2001. How has the world changed since the 9/11 attacks? Is the west stronger or weaker? And are we any safer now than we were then? We hear from some of the British military personnel involved in the evacuation effort at Kabul airport, and find out what might happen to Britain’s nuclear deterrent if Scotland votes for independence in a second referendum. Plus the continuing problems with the Ajax armoured vehicles, and we look inside NATO’s newest command, designed to cover the alliance’s back in a crisis.