Tunisia attack: To prevent more bloodshed we must accept that containment has not worked

Effective action to prevent further attacks by Isis-inspired gunmen requires a recognition of the failure of the policy of containment of Isis pursued over the last year by the US, Britain and their allies. Isis is getting stronger not weaker. In the aftermath of an atrocity like Sousse, it would be naïve to expect David Cameron to admit to this failure and to recommend new and more effective policies.