Here's What Radical Islam Looks Like In The UK

The United Kingdom raised its terror threat level to "severe" on Friday in response to the rise militant Islamists in Iraq and Syria, some of whom came from Britain.

Around 500 British Muslims are estimated to have joined groups like ISIS, along with more than a thousand volunteers from other Western countries. Notably, the murderer of American James Foley in video released by ISIS appeared to have a British accent.

In a statement delivered from Downing Street in London Friday afternoon, U.K. Prime Minister David Cameron said Britain was facing a "greater and deeper threat to our security than we have known before."

He said confronting ISIS was part of a generational struggle that he thought could last decades.

"Poisonous ideology of Islamist extremism is the root cause of the terror threat," Cameron said. "We will always act with urgency when needed."

History Of Terror

Radical Islamist leaders used to preach openly in the U.K, Innes Bowen, a BBC journalist and author of "Inside British Islam," tells Business Insider.

In 2004 Bowen attended a gathering held by notorious radical preacher Omar Bakri Muhammad, who later left Britain and was charged with terrorism-related offenses in several countries. She was struck by the pro-al Qaeda message that she heard in the wake of the September 11 attacks, and "almost as striking was how 'normal' the atmosphere was."

"I was in the women's gallery where everyone was very friendly towards me even though they knew I was a BBC journalist. Small children played while the husband of one of the women praised al Qaeda from the pulpit downstairs - but that was before the London bombings," she said.

Bowen tells us this radical assembly was far from being a typical Muslim crowd.

"They were all supporters of this extreme group - now banned - called al Muhajiroun," she said.

One member of the group told her, "We consider 9/11 as a self sacrifice operation whereby 19 Mujahideen, fighters of Islam, broke the nose of America."

But the era of open radicalism ended on July 7, 2005, when three British Islamists detonated suicide bombs on the London Underground, and a fourth blew himself up on a double-decker bus.

The blasts killed 52 and injured up to 700.

Aged 18, 19, 22, and 30, three of the bombers were British-born Pakistanis, and another had immigrated from Jamaica.

After 2005, many radicals were either imprisoned or went abroad.

Burning underground

Government responses to the 2005 attacks appear to have pushed the current wave of Islamism underground, leading Islamist leaders to become more cautious.

The New York Times reports that a small minority of radical imams preach Islamic supremacy, taking aim at non-Muslims and gays and citing fundamentalist interpretations of the Quran to justify violent responses.

However, as the Kimiko de Freytas-Tamura writes in The Times, "They are careful not to suggest taking up arms, but will talk about the situation in Syria, Iraq or Gaza, and then talk about a Muslim's duties. Their views are extreme, but rarely illegal."

One of the most prominent preachers is Anjem Choudary, whose followers were recently caught handing out pro-ISIS leaflets.

Choudary generates headlines with his colorful damnations of Western governments, and his twitter feed boasting of appearances on NBC and Fox as well as European networks.

His proclamations mix concerns over torture, drone-warfare, and Muslim persecution with conservative Islamism and rhetoric of an epic clash of civilizations.

But with no mosque that will have him, Choudary holds lectures and town hall meetings, posting recordings on YouTube.

Recruits for Syria and Iraq

As a result of the conflict involving ISIS, the radical message has gone public again.

"This time it is being spread by fighters abroad via social media rather than by preachers based in the U.K.," Bowen said.

ISIS has been targeting Western recruits with social-media campaigns, slickly produced videos, and English-language publications.

Bowen said some radicals may well versed in religious ideology and have a misplaced sense of duty, while others are motivated by a sense of adventure and could be "surprisingly ignorant."

The New Republic recently reported that two young men who joined the conflict from the U.K. this May purchased "Islam for Dummies" and "The Koran for Dummies" before leaving.

It's difficult to identify who is at risk at radicalization, though.

"If we look at the backgrounds of the British Muslims who have been involved in violent extremism, what's striking is the variety: graduates as well as the poorly educated; women as well as men; the privileged as well as the marginalized; converts as well as born Muslims; British born as well as immigrants," Bowen said.

"The only thing that those so far convicted of terrorist offenses in the U.K. have in common is a shared ideology and a willingness to act on it."