BEIRUT — An al-Qaida splinter group that has seized a huge chunk of northern Iraq commands as many as 10,000 fighters and has steadily been consolidating its hold on much of northeastern Syria across the border.
Its pursuit of an Islamic state that would straddle the two countries has thrown it into bloody conflict with both governments, Kurdish militias and Syrian rebels of all stripes. The group, known as the Islamic State of Iraq and the Levant, has employed a calculated strategy to achieve its aims, using everything from beheadings to terrify opponents to ice cream socials for children to curry favor with local populations under its control.
But it is the group's military prowess that has brought under its sway a swath of territory that stretches from the Syrian-Turkish frontier in the north down the Euphrates River all the way to the Iraqi city of Fallujah just 65 kilometers (40 miles) west of Baghdad.
This week, the group's fighters, many of them in fast-moving pickup trucks mounted with machine guns, captured Iraq's second-largest city, Mosul, before barreling south to take the city of Tikrit — two urban centers in the heartland of northern Iraq's oil industry.
The Islamic State is the latest and most powerful incarnation of what began as an al-Qaida affiliate in Iraq following the 2003 U.S.-led invasion. American forces spent years and enormous resources to bring the group largely to heel before U.S. troops pulled out of the country in December of 2011.
Since then, the region has been convulsed in political turmoil and sectarian hatreds. The Islamic State has seized on those Sunni-Shiite tensions to help whip up its Sunni extremist followers.
The group is led by an ambitious Iraqi militant known by his nom de guerre of Abu Bakr al-Baghdadi with a $10 million U.S. bounty on his head. After taking the reins in 2010, al-Baghdadi successfully transformed what had been an umbrella organization focused mainly on Iraq into a transnational military force.