In recent months convicted terrorists just released from prison have launched knife attacks which have maimed and killed - the latest one on Streatham High Street in South London. Both attackers were shot dead by police officers.

David Aaronovitch asks why events like these are happening, and whether we are releasing convicted terrorists too early. The government is promising swift action, but will the proposed changes make us safer?

He asks what we know about the success of de-radicalisation programmes in our prisons and whether there are lessons we should be learning from other countries.

Contributors:

Nazir Afzal, former Chief Prosecutor

Andrew Silke, Professor of Terrorism, Risk and Resilience at the Cranfield Forensic Institute

Lord David Anderson QC, former Independent Reviewer of Terrorism Legislation in the United Kingdom

Dominic Casciani, BBC Home Affairs Correspondent

Producers: Rosamund Jones, Kirsteen Knight, Jordan Dunbar and Tom Wright