So if an airline was hijacked or there was a suspected terrorist threat onboard over British airspace the RAF wouldn't be sent up? The RAF would just sit back and let whatever was going to happen, happen? Get real. What the yanks did was no different to what the British, French, Germans, Italians, Spanish etc would do if there was a suspected threat.
Don't you all remember what happen a month ago? The RAF sent a Typhoon to intercept a bloody helicopter that squawked the wrong code.
