Video showing the brutal beheading of kidnapped American journalist James Foley is only the latest episode of barbarity carried out by the Islamic State of Iraq and al-Sham.
The extremist network — known as ISIS — raised its profile in May after seizing major Iraqi cities and towns in a bid to overrun the central government in Baghdad and establish an Islamic state. Foley’s execution, now confirmed by the U.S. government, gives ISIS the exposure it craves while inciting jihadists with its bloodthirsty campaign of destruction.
Here are some things to know about ISIS.
Where did ISIS come from?
The terror group, made up of Sunni extremists, originated from al Qaeda in Iraq in the mid-2000s. Prominent jihadist Abu Bakr al-Baghdadi emerged as a leader in 2010, transforming the fighters into a cohesive unit.
The group became known as the Islamic State of Iraq and the Levant (or the Islamic State of Iraq and al-Sham) in April 2013, when Baghdadi said his militants were also fighting in Syria. ISIS remains the largest terror organization in Iraq, with its numbers estimated in the thousands.
What are they trying to accomplish?
In June, ISIS declared its occupied territory as a caliphate — or an Islamic state governed by Sharia law — and rebranded itself as the Islamic State. But its goal to overthrow the Shiite-led government in Iraq has slowed in recent weeks, despite initial successes capturing parts of northern Iraq.
ISIS’s attempt to maintain control of a key location — the Mosul Dam, which supplies power and water to millions of people — failed after the U.S. intervened with airstrikes this month. Those strikes helped Kurdish and Iraq forces drive out ISIS fighters from the dam.
After news broke Tuesday that ISIS had executed Foley, the U.S. launched more strikes overnight against ISIS near the Mosul Dam.
What are some of ISIS's alleged atrocities?
In communities overrun by ISIS, survivors have shared stories of torture and slaughter. Photos posted online show scenes of men — purportedly ISIS prisoners — being marched with their hands tied then getting shot in the back of their heads.
The Islamist extremists have been blamed for massacres of dozens in some towns, decimating in particular an ancient religious minority known as the Yazidis. Tens of thousands have been driven from their homes and fled, desperate to escape religious persecution.
Some were forced to flee to Mount Sinjar, where the U.S. earlier this month dropped food and water to the stranded. Those in refugee camps told NBC News that they witnessed the shootings and beheadings of innocent people — including children — and the rape and capture of women. Other reports have victims being buried alive.
The Christian minority in Mosul has also described being run out by ISIS. If they wanted to stay, they had to convert to Islam or pay a tax, they told NBC News. Otherwise they would be killed.
Why did they kill James Foley?
The execution of Foley, who went missing in Syria in November 2012 and who the U.S. tried but failed to rescue, appears to be in retaliation for the latest wave of American airstrikes targeting ISIS in Iraq. But the dissemination of the video falls in line with a larger public-relations campaign. ISIS has previously posted recruitment videos featuring its fighters — some claiming to be citizens of Western countries such as the United States, Britain and Australia — urging others to join the group’s ranks.
ISIS has been successful at using online platforms, including Twitter and YouTube, to draw attention and encourage others to join the group's cause. At one point, the ISIS hashtag jumped from about 1,000 hits before its Iraq invasion to between 30,000 and 40,000 hits on some days, a researcher with the International Center for the Study of Radicalization in London told NBC News.
In addition, ISIS has two English-language magazines and a newsletter meant to win the hearts and minds of Muslims. The full-color glossies include pictures of alleged infidels who were blindfolded and about to be executed as punishment for going against the Quran, the sacred Islamic text.