British Prime Minister Explains Why Islamic State Threatens Security Like Never Before

British Prime Minister David Cameron laid out the threat terror group ISIL poses, after raising his country's threat level to indicate that an attack is "highly likely."

"What we're facing in Iraq now, with ISIL, is a greater and deeper threat to our security than we have known before," Cameron said.

He went on to draw out a contrast between ISIL and other terror groups: "In Afghanistan, the Taliban were prepared to play host to al Qaeda, a terrorist organization. With ISIL, we are facing a terrorist organization not being hosted in a country, but actually seeking to establish and then violently expand its own terrorist state."

"And with designs on expanding to Jordan and Lebanon, right up to the Turkish border," he warned, "we could be facing a terrorist state on the shores of the Mediterranean and bordering a NATO member."

Cameron said the threat was not caused by Iraq war, but by a "warped version of Islam": "The root cause of this threat to our security is quite clear. It is a poisonous ideology of Islamic extremist that is condemned by all faiths and by all faith leaders. It believes in using the most brutal forms of terrorism to force people to accept a warped worldview and to live in an almost Medieval state."

The prime minister noted that the execution of American journalist James Foley by a member of ISIL who "increasingly seems to have been a British terrorist" was "clear evidence, not that any more was needed, that this is not some foreign conflict thousands of miles from home that we can hope to ignore."