Civilians ride a motorbike past an advocacy office that belonged to Islamic State fighters in the town of Tel Abyad, Raqqa governorate, June 19, 2015. REUTERS/Rodi Said The Islamic State rules over the areas it controls using fear tactics to terrify its populace into submission, and its leaders are proving themselves to be quite paranoid as the militant group loses some ground.

"The Islamic State has turned cartoonish violence into real-life tragedy as a means of control," strategic security firm The Soufan Group reports.

"Yet the state of fear cuts both ways, and the Islamic State is increasingly terrified of the people it claims to protect and rule."

Unlike other terror groups, the Islamic State (also known as ISIS, ISIL, and Daesh) sees seizing and controlling territory as essential to its mission and purpose.

The terror army has declared a "caliphate," a 7th-century-style Islamic empire that aims to unite the world's Sunni Muslims under a single religious and political entity, in parts of Iraq, Syria, and beyond.

ISIS militants enforce a strict interpretation of Sharia law, punishing crimes with physical abuse and banning music and cigarettes.

ISIS also leaves bodies in the street of its de facto capital of Raqqa in Syria and releases propaganda videos showing brutal executions as part of its scare tactics to keep people in line.

"Sunnis are indeed being given a stark choice: Either you accept the caliphate, renounce the international [US-led] coalition and its proxies, or you will meet with ignoble death, of which even your own families won’t want to speak," ISIS experts Michael Weiss and Hassan Hassan wrote in The Daily Beast this week.

"You will not be martyred; you will be tried and found guilty, branded a turncoat to your faith, abominated as a murderer of your fellow Sunnis, and destroyed as something less than a human being."

In addition to using these fear tactics to ward off an uprising, ISIS goes to great lengths to protect its positions and weed out possible spies within its ranks.

Soufan notes that "the recent videotaped execution of 15 alleged spies demonstrates just how afraid the group is of internal revolt through informants and potential Sunni tribal opposition."

The paranoia makes sense, considering that many top ISIS leaders are former Iraqi intelligence officers from ousted-dictator Saddam Hussein's regime, as Christoph Reuter of Der Spiegel reported.

Haji Bakr, the former Iraqi colonel credited with creating the blueprint for ISIS, had modified "Saddam Hussein's omnipresent security apparatus, in which no one, not even generals in the intelligence service, could be certain they weren't being spied on," Der Spiegel reported.

The Institute for the Study of War

Some ISIS policies reflect this experience with intelligence tactics: The group reportedly banned GPS-enabled devices in its territory to avoid giving away the positions of certain locations that could be targets for US air strikes.

This fear turned out to be legitimate. Earlier this month, the US Air Force struck an ISIS headquarters location after an intelligence team geo-located the building based on a social-media comment from an ISIS militant. Despite the apparent ban on GPS-enabled devices, ISIS recruiters still access social media to lure new people into the "caliphate."

Ultimately, however, air strikes aren't likely to take out ISIS on their own. The real danger to ISIS' survival is a Sunni uprising against the militants.

Members loyal to the Islamic State wave IS flags as they drive around Raqqa on June 29, 2014. Reuters Weiss and Hassan point out that Sunnis in Syria and Iraq are crucial to the survival of ISIS, noting that Sunnis are ISIS' "core constituency and the only demographic force that can ultimately unhorse it on the battlefield."

"Without this group, ISIS’s self-portrait as the true custodians and defenders of the Sunnis in the mosques and souks and cafes — from Raqqa City to Fallujah — falls to dust."

ISIS has used the atrocities committed by Shia militias in Iraq and the Assad regime in Syria against Sunnis as a recruiting tool in an effort to convince Sunnis that ISIS is the only true protector of the Sunni populace.

But considering how brutal ISIS rule has become, it's unclear if this tactic is sustainable.

"The Islamic State knows all too well the destructive power of spies and so-called 'sleeper cells,' as these tactics have played an integral part in most of its successes, even predating the current iteration of the group," The Soufan Group noted.

"With defenses and attention guarding against the external threat, the impact of a relatively small internal threat is amplified. ... It does not take much to destabilize a rigid system built on forced compliance, especially with external threats growing in such public and visible fashion."