What have and haven't we learned about extremism since 9/11?

Two decades on from the deadliest terror attack on US soil, the effects on air travel, surveillance and anti-Muslim sentiment continue to be felt.On the Sky News Daily podcast with Dermot Murnaghan, we are joined by Nick Aldworth, a former police counter-terror national coordinator, and Imam Usama Hasan, who talks about being a young Muslim man at the time and the importance of dialogue to combat extremism.Daily podcast team:Senior podcast producer - Annie JoycePodcast producer - Nicola EyersPodcast researcher – Rosetta FourlagawoPodcast researcher – Faye de Silva Interviews producer - Tatiana AldersonInterviews producer – Alys BowenArchive - Simon WindsorArchive - Rob FellowesArchive - Nelly StefanovaMusic - Steven Wheeler