Airstrikes in response to the kidnapping of a British citizen would be an "overreaction", a former senior member of the armed forces has told ITV News.
However, Major General Jonathan Shaw, a former assistant chief of defence staff, said engaging in such attacks may make up part of a wider strategy to tackle the threat of the Islamic State as a whole.
He added that the Government's response to the hostage threat would be "well-worn", and would not involve negotiating with kidnappers.
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.