BEIRUT (AP) — Across the broad swath of territory it controls bridging Syria and Iraq, extremist militants from the group known as the Islamic State have proven to be highly organized administrators. Flush with cash, they fix roads, police traffic, administer courts, and have even set up an export system of smuggled crude from oil fields they control.

But the extremists — a mix of Iraqis and Syrians but also foreign fighters from Arab countries and non-Arab regions like the Caucasus — run the risk of provoking a backlash from the people they have come to rule.

Unlike Lebanon’s Hezbollah or the Palestinian militant group Hamas, which have deep roots in their communities, the Islamic State group is not a grassroots movement and its sway over its populations is ultimately based on violence, not necessarily a groundswell of support for its vision of a hardline Islamic caliphate. While it has been welcomed by some disenfranchised Iraqi Sunnis as potential saviors from the Shiite-dominated government in Baghdad, many consider the group an alien entity.

In recognition of that, the group has varied the imposition of the radical version of Islamic law they advocate. In their main stronghold in Syria, the city of Raqqa, they have unleashed it without reserve, killing perceived offenders and cutting off the hands of thieves in public.

But in Iraq’s second largest city, Mosul, they have been more cautious. They’ve taken some steps like banning alcohol and painting over street advertisements that show women’s faces — but have held off on strict punishments for now.