Britain is at greater risk of a Paris-style terror attack as so-called Islamic State (IS) loses ground in Syria and Iraq, a top coalition spokesman has warned.
IS, also known as Daesh, are "beginning to crack" under the pressure of Western-backed air strikes and attacks on their recruitment and finances.
But as they are being "squeezed" in their so-called caliphate, they are more likely to lash out and carry out atrocities in the West to assert themselves, Colonel Steve Warren, spokesman for the anti-IS coalition, said.
He said: "As we squeeze them and we begin to see them get chipped away at inside Iraq and Syria, we are going to see them look for other avenues.
"We have seen this in Libya, we have seen it in parts of North Africa and Afghanistan, we have seen this through high visibility terror attacks in places like Paris, possibly San Bernardino, Ankara, other places.
"What I do know is that we have assessed that as we continue to squeeze this enemy, as this enemy continues to feel that it's back on its heels, our assessment is that one of the responses to that - it really is in desperation, that they are going to want to show the world that they are still viable - and one of the ways they can do that is through a high visibility attack outside of their so-called caliphate borders."
He said an attack like the one in Paris, when 130 people were killed in co-ordinated strikes across the city, is not a sign of strength.
"We view it exactly the opposite", he said.
"We view it as a sign that because of the pressure that has been placed on them, because they are beginning to stumble a little bit, they are trying to either distract or prove that they are not finished yet."