And if you read more fully about al-Harith you will learn he only went off the rails and became radicalized a few years ago.

It is tragic he killed people.  It is tragic that he left his five children orphaned.  His wife was not radicalized, but went to live for a while, in the horrible, horrible Islamic State, because she was willing to try anything to convince him to return to a peaceful life in the UK.  She risked her life going there, and she risked her life escaping from IS.  That too is tragic.

People balk at the $1 million settlement al-Harith and the other 17 UK captives got.  Okay, but Guantanamo is the most expensive prison in history.  If I recall correctly prisoners cost $60,000 per year in a US supermax, and a third that for a minimum security.  Guantanamo used to cost $1 million, per prisoner, per year! $10 million each next year!

It would have been far cheaper to send them home, and give the a generous monthly allowance, if they can show they are behaving themselves