The United Kingdom has raised its terror threat level to "severe" in response to the advances of the Islamic State, Prime Minister David Cameron announced on Friday.
Cameron, in a televised statement from London, said it was the first time in three years that the nation's threat level had been that high. It had previously been at "substantial."
A "severe" threat level means an attack is "highly likely," Cameron said, although he did not cite specific intelligence.
The change was made by Britain's Joint Terrorism Assessment Centre following ISIL's advance in Iraq and Syria and its videotaped beheading of American photojournalist James Foley earlier this month. Cameron noted the British accent of Foley's killer in the video, and he said "at least 500" people have now traveled from Britain to fight with ISIL in Iraq and Syria.
ISIL, Cameron said, presents "a greater and deeper threat to our security than we have known before."
He called the Islamic State "a poisonous ideology of Islamist extremism" that must be confronted head-on.
"We cannot appease this ideology. We have to confront it at home and abroad," Cameron said.
Cameron's approach to countering ISIS is winning praise so far.
Cameron calls this a "generational struggle against a poisonous ideology." He says we'll be fighting for "years" and possibly "decades."- Charles C. W. Cooke (@charlescwcooke) August 29, 2014
Islamic State militants have "warped world-view", forcing people to "live in almost medieval state", UK PM says http://t.co/Fu85UjMEbd- BBC Breaking News (@BBCBreaking) August 29, 2014
British PM's statement on radical Islamism stronger, more articulate, more intelligent and more moral than America's. #AmericaErodes- Kurt Kramer (@kmatskramer) August 29, 2014
David Cameron is forcefully controlling this press conference. I bet more than a few Americans would vote for him- HowardKurtz (@HowardKurtz) August 29, 2014
David Cameron sounds like a man with a strategy.- Matthew Continetti (@continetti) August 29, 2014