Paul Crompton As the Islamic State of Iraq and Syria has captured vast swathes of territory, analysts are questioning how long the militant Al-Qaeda offshoot can maintain control. The group's shock takeover of Iraq's second-largest city Mosul in early June gave it a firm foothold to establish its expansive Islamic state. ISIS has so far largely deflected attacks from the beleaguered army of embattled Iraqi Prime Minister Nouri Al-Maliki. Those living in the self-declared caliphate can now obtain Islamic State passports, and read the group's print and online newspaper in different languages. ISIS's apparent commitment to organized governance has led it to tear down security barriers to open roads, restore electricity lines and pay municipal employees. Under Abu Bakr Al-Baghdadi — also known as Caliph Ibrahim — ISIS maintains a full-time staff of around 1,000 medium to top-level field commanders. Monthly salaries range from $300 to $2,000, a considerable amount given that Iraqi government workers last year reportedly made only $400. ISIS also pays low-level fighters. However, keeping its towns and cities running smoothly could hinder its existence due to the vast cost of maintaining the caliphate, one expert said. Its financial operations include selling crude from oil fields under its control, robbing banks, and taxing trucks that cross its borders. However, ISIS is unlikely to have enough resources to continue operating at its current level, said Charles Ries, a former US ambassador who serves as a vice president at the Rand Corp think tank. “I don't see that situation as sustainable from the economic standpoint,” Ries said, US channel CNBC eported. Northern threat To help make financial ends meet, ISIS is likely to try to take over more oil fields around Iraq, said David Ottaway, a senior scholar at the Woodrow Wilson Center, and a former Washington Post Middle East correspondent. “They're going to need a lot more money than they've gotten so far,” Ottaway told Al Arabiya News. In its quest for oil, a prolonged conflict with the Kurdish-controlled north is likely, he added. “That's why they're going to start going after oil fields in Iraq, which is where I expect them to come up against Kurdistan,” Ottaway said. ISIS could also come under pressure from other Sunni groups operating within its borders. “The Sunni — former Baathist — elements and tribal groups are going to turn on ISIS,” leading to “a civil war within a civil war,” Ottaway said. This will have further consequences for Maliki's primarily Shiite government. “Even if the anti-ISIS Sunni groups did prevail, they're going to want a new political order in Iraq and a lot more autonomy for the Sunni areas of Iraq,” Ottaway said. Historic questions Another possible decider to the future of the caliphate is the response from the international and regional community. Countries bordering Iraq have so far adopted mainly defensive stances. Although US President Barack Obama has called for “vigilance” over the threat posed to American regional interests, he has not made any commitments to stamp out ISIS. “What we can't do is think that we're just going to play whack-a-mole and send US troops occupying various countries wherever these organizations pop up,” Obama told American TV channel CBS last month. In late June, Custodian of the Two Holy Mosques King Abdullah ordered “all necessary measures” to protect the Kingdom from the threat of terrorism. Some 30,000 Saudi soldiers were deployed to the desert border with Iraq, Al Arabiya News Channel reported in early July. A Jordanian government spokesman said in June that a military build-up on its Iraq border was merely “precautionary,” Agence France-Presse reported. A potent threat to ISIS could come from Shiite-led Iran, said Ottaway. Tehran has continually worked to militarily prop up Maliki's regime, most recently in the form of Russian-made jets specifically intended to be used against ISIS. The group's staying power in Iraq and Syria could hinge on the level of acceptance in the Muslim World, said David Mack, a former US ambassador and scholar at the Washington-based Middle East Institute. Baghdadi's decision to declare himself caliph and demand the loyalty of all Muslims “calls into question the staying power of this movement,” said Mack. Historically, “pretenders to the caliphate” have never fared well, Mack said, citing the fall of Baghdad from the 13th century Abbasid Caliphate to Mongol invaders. — Al Arabiya News