Its a difficult situation. Not sure we're quite at internment yet, but stricter actions required.
No more new mosques, ones with links to hate preaching closed. Make it difficult as difficult as possible by disrupting networks.
This bomber was born and raised here, like so many others so very difficult to keep tabs on everyone.
I agree with comments above, close off flights to Syria and the like, and interview anyone who wants to travel to countries nearby at length. Stop them if they have no justifiable reason to go.
Trouble with keeping convicted ones in prison is that they are radicalising others whilst inside.
Perhaps a large converted tanker or such like anchored in the north sea with solitary confinement.
No visitors, radios, TV or internet.
Fuck em.