Britain is moving towards joining American airstrikes against IS "probably sooner rather than later", a defence expert has told Good Morning Britain.
Professor Michael Clarke, who heads the Royal United Services Institute, said British involvement in Iraq was "not inevitable" and that David Cameron was eager to avoid a repeat of last years vote on Syria.
I've been told at the Nato summit that the intelligence services know exactly who 'Jihadi John' is - or at least are 99.9% certain.
The British aid worker being held by Islamic State is David Haines, a 44-year-old father-of-two from Perth, Scotland.
In a video statement which claims to record his final words US hostage and journalist Steven Sotloff blames US foreign policy for his death.