On one recent Thursday, Abu Jassim received a text message from a provincial leader of the Islamic State (Isis). Abu Jassim, from a tribal area in eastern Syria, was asked to lead the Friday prayers at a nearby mosque, known to be a stronghold of the Sufi order al-Khaznawi. Although he had no experience as a mosque imam, Abu Jassim told the usual preacher that he would take his place in compliance with the Isis orders. His sermon focused on the misguidance of Sufi practices, to the dismay of the local worshippers.

Two days later Abu Jassim was summoned by the jihadi group’s regional emir and disappeared for several days before he was finally released. According to one of his relatives, a local resident had tipped off Isis that Abu Jassim was one of the rebels who had fought Isis a few months before it took over his area. Abu Jassim told the Isis leader that he had stopped fighting Isis long before they overran his area and that he had joined the group on his own volition, which is why they agreed to release him.

The incident is one example of a range of tactics employed by Isis to govern areas under its control. Isis could have sent one of its 12 members permanently stationed in that village, but chose to send a second-tier local member who was not qualified as an imam to preach to a Sufi audience. The move, according to extensive conversations with influential residents in eastern Syria and in Iraq, is part of a successful strategy of divide and rule which Isis has followed in its territories.

It is worth emphasising that Isis – in its current and former incarnations – has operated among tribes for around 10 years, and has mastered to a large degree the game of dancing around tribal fault lines. Today the areas under the group’s control are predominantly tribal, from Minbij in eastern Aleppo and Uqayribat in the Hama eastern countryside to the Iraqi town of Jalawla in Diyala. In these areas, increasing social and tribal rivalry and hostility are more visible than any unified enmity to Isis. In Syria, Isis is the first fighting faction to successfully pit tribes and members of a tribe against each other.

In newly captured areas in Deir el-Zour, for example, convoys of residents visit the Iraqi border town of al-Qa’im to meet the Isis leader in charge of “tribal affairs” to gain the trust of the jihadi group and present themselves as better suited for positions in its areas. “People are racing to win the trust of Isis,” one resident told me. Other sources say Isis members from a certain area tend to be more aggressive against their own people than members from outside. The killing of hundreds of men from the tribe of Shai’tat in August is often blamed on members of that tribe or their blood-related clans.

Since Isis split from Jabhat al-Nusra in April last year, it has secretly sought to buy the loyalty of influential tribal leaders. Such alliances would include a pledge to share financial revenues and promote such figures for future influential positions in their societies at the expense of existing leaders. Isis would mostly target the younger leaders of a tribe, who tend to have more credibility because they played a leading role in the anti-Assad uprising, unlike the older generation who stuck with the Assad regime. Last year, before Isis became a force in the town of Al-Bukamal, a tribal figure related such machinations employed successfully by Isis within his own prominent tribal family.

It was such a strategy that helped Isis swiftly take otherwise impervious towns in Deir el-Zour in the summer, such as Mo Hassan, Sha’itat and Al-Bukamal. In Mo Hassan, for example, the takeover was surprising to most rebels in the province as the town is known to be hostile to Isis and its residents known to be seculars and previously heavily involved in the Assad army. Isis had bought the loyalty of key rebel and tribal figures in those areas who, along with the massive stockpiles seized in Iraq, helped it gain quick control of their towns. Isis also used such figures to preempt any plan from regional countries to organise tribes against it, by attending such meetings, as happened in tribal meetings organised by Gulf countries.

A key reason for the success of the strategy of divide and rule is that Isis allows local forces to govern their own state of affairs, which increases rivalry and reduces the visibility of Isis. That is particularly the case in areas where Isis is in need of manpower. Such local forces, who pledge their allegiance to Isis but are not admitted to its core structure, would serve municipality and policing roles.

But Isis still has an over-arching presence in these areas, in the form of a mobile checkpoint. Typically, Isis members would hide their weaponry in a house and show minimum force in public. Such weapons and fighters, with often exaggerated reinforcement from nearby areas, would be deployed if Isis were attacked.

These policies mean that the local population has little motivation and huge deterrent to rise up against Isis, particularly in the absence of a viable and acceptable alternative. Such policies also make it much harder for any force from outside to retake these areas from Isis, owing to the difficulty of filling the void and forming new alliances with the local communities.

Given these dynamics, the idea of encouraging tribes to rebel against Isis is currently an illusion. The air strikes have forced Isis to change its military tactics, but for the local communities the air strikes are no more than noise in the background. They have not had a meaningful impact on the ground – despite claiming the lives of more than 500 Isis and al-Nusra fighters – except in so far as prices of food and fuel have gone up.

Also, it is worth noting that the fighters Isis deploys to the front lines, who are more exposed to the air strikes, tend to be from outside the group’s core members. They are mostly new members whose death will not disrupt the group’s long-term capabilities in a substantial way. And with the increased activities of the Assad regime because of the air strikes, the international action is viewed as a threat rather than a rescue, a perception that additionally plays into the hands of Isis.

Isis has a strategy, and longtime experience, in dealing with the communities under its control. The group’s presence can be challenged only through an effective counter-strategy that takes into consideration the complexities of the situation on the ground and the reasons that make Isis able to hold a tight control over these territories. While strikes from the air might be effective in restricting Isis movement, more work needs to be done on the ground.

Hassan Hassan is an analyst with the Delma Institute, a research centre in Abu Dhabi. @hxhassan