The Islamic State (IS) group is like ‘the Nazis at their worst’, a former head of the Royal Navy has said.
Admiral Lord West said the extremists were bent on destroying the British state and countries in the west must use everything in their armoury to eradicate them.
He said he was confident IS would be defeated, but warned it could take up to 20 years.
IS forces have been targeted in air strikes in Iraq and more recently Syria, while they have horrified the world with videos of hostages being beheaded — including British captive David Haines.
Lord West said he expected the UK to join operations over Iraq but also backed action in Syria, which was fraught with political and legal complications.
He said: ‘We are fighting a group who are killing British citizens and... wish to destroy the British state.
‘One of the purposes of the armed forces is to look after the security of the state. You’ve got a group who are like the Nazis at their worst.
‘We have to use everything in our armoury to destroy them.
‘They might think they can get away – they can’t.
‘It might take 20 years but we will get them.’
The US Navy has delivered a barrage of cruise missile attacks on IS targets this week.