BAGHDAD (NYTIMES) - The Islamic State, born of an insurgency, quickly seized control of much of Iraq and Syria. Now, having lost much of its territory but far from defeated, the militant group is returning to its roots.
Until 2014, the Islamic State in Iraq and Syria (ISIS) was affiliated with al-Qaeda. By that time, ISIS, which got its start in Iraq, had established a foothold there and in Syria. It shocked the world in June 2014 as it took over more than 50 places, including Mosul, Iraq's second-largest city.
In the past four years, ISIS has carved out a sprawling territory across Iraq and Syria through military dominance of more than 127 critical places. The group governed the residents of dozens of cities and towns, and it benefited from their taxes. The militants also had control over strategic locations, like military bases and border crossings, as well as economic assets, like oil fields and dams.
U.S.-backed forces pushed the Islamic State out of Raqqa, the group's de facto capital, last week, dealing a heavy blow to the militants in a year in which they lost much of their territory.
The offensive in Raqqa began in June and left widespread destruction, displacing about 270,000 residents. US-led coalition airstrikes there were "reportedly killing hundreds of trapped civilians every month," Samuel Oakford wrote in a report for Airwars, a nonprofit group that tracks reports of civilian deaths in Iraq and Syria. According to the report, the coalition has confirmed four civilian deaths in the battle for Raqqa.
With the fall of Raqqa, ISIS has lost two of its most important cities in three months.
In July of this year, the Iraqi government announced that it had finally retaken control of Mosul after three years of ISIS rule and a brutal nine-month battle. Iraqi forces faced stiff resistance from ISIS militants there, often in dense urban areas that were difficult to navigate. Much of the city was destroyed.
Mosul held huge symbolic value for the group. It was there, in June 2014, that Abu Bakr al-Baghdadi, the leader of ISIS, declared a caliphate after his fighters took control of Mosul and swept through other parts of northern Iraq and Syria, seizing dozens of cities.
ISIS' remaining strongholds in Iraq fell quickly after Mosul was retaken. Tal Afar, near Mosul, was captured by Iraqi forces in an offensive that lasted just 11 days. And this month, the militants barely put up a fight in Hawija.
The remaining area of ISIS control in Iraq stretches across the Qaim border crossing into Syria, where ISIS maintains a shrinking swath of territory along the Euphrates River.
Downstream of Raqqa, in resource-rich Deir al-Zour province, the group is under pressure from two sides.
The US-backed forces that seized Raqqa have been advancing southeast into the province. And last month, the Syrian government broke a nearly three-year siege by the militants of a government-held pocket of territory in Deir al-Zour city. Government forces, backed by Russia and Iran, have since advanced to retake Mayadin, where coalition officials believed many of the ISIS leaders had relocated from Raqqa.
Despite these sharp losses, analysts say that ISIS is not defeated. An estimated 6,000 to 10,000 militants remain in Iraq and Syria.
ISIS has been shifting tactics and returning to its insurgent roots. Analysts say it will continue to have some local support and the ability to lodge attacks throughout the region.
"The networks will survive and the insurgency will continue in these areas, probably under a different brand," says Columb Strack, a principal analyst at IHS Markit.