The recent advances of the Islamic State of Iraq and Syria (ISIS), since redubbed Islamic State, in northern and western Iraq brought into focus the profound ideological and sectarian cleavages that drive the conflicts in both Iraq and Syria. But there is more to the story than a puritanical Sunni rebel movement seeking to unseat Shiite apostate rulers and revive the caliphate in the Middle East. IS  is also gaining momentum in the struggle to control two natural resources that have defined the history of the Middle East – oil and water.

With its conquest of Mosul and Tikrit, IS gained a stranglehold over Iraq’s northern oil export pipeline and the country’s largest refinery. As Iraqi security forces retreated in disarray, the Kurdish Regional Government (KRG) sent its Peshmerga army to defend Kirkuk, site of Iraq’s largest oil fields. More than just blocking IS’s encroachment, the move turns the Kurds’ long-standing claim to Kirkuk into a fait accompli. The KRG has already sent oil through its own pipeline to Turkey and onward to Israel, bolstering the KRG’s network of regional alliances and potential supporters of Kurdish independence. Meanwhile, every diverted barrel is a direct hit to Baghdad’s budget.

Less noticed, but equally consequential, is the battle over water. If control of oil has driven economic development in the modern Middle East, control of water has been a fundamental component of civilization itself. For decades, both the Syrian and Iraqi governments focused on hydrology in their bids for socioeconomic development, building a bevy of dams, canals and other infrastructure to control floods, improve agricultural irrigation and generate electricity for their populations. Denying or diverting water, though, was also tantamount to war. During the Iran-Iraq War (1980-1988) Saddam Hussein fretted that Iran would destroy dikes and dams on the upper Tigris River in order to cause flooding in Baghdad. In the early 1990s Syria and Iraq nearly went to war with Turkey over plans to divert part of the Euphrates River, and in 1992 Iraq famously cut off the water to the marshes of southern Mesopotamia in order to destroy the terrain where Shiite insurgents were hiding out. Punishing drought conditions in rural Syria may even have caused social unrest that helped precipitate the beginning of the March 2011 uprising.

Now, it is IS’s turn to flex its hydrological muscles. In February 2013, IS took control of the Tabqa Hydroelectric Dam (Syria), once a showcase in Hafez al-Assad’s development plan and a major electricity source for Aleppo. Earlier this spring, IS opened up dikes around Fallujah to impede the Iraqi army as it tried to besiege the stronghold, causing flooding as far away as Najaf and Baghdad. With its recent advances, IS now controls the hydroelectric dam at Mosul, Iraq’s largest, and IS  is poised to take the dam at Haditha, the country’s second largest. With the tables turned, the Iraqi government finds itself considering a preemptive opening of the Haditha floodgates to block IS’s path.

The addition of a resource war dynamic in the midst of the already significant ideological and sectarian cleavages in Iraq and Syria is hardly welcome news. Whether it’s coltan in Congo, coca in Colombia, poppies in Burma and Afghanistan, oil in Nigeria or blood diamonds from Sierra Leone, natural resources have taken center stage in some of the world’s bloodiest and most protracted civil wars. Most researchers point particularly to the “lootability” of resources – whether they are easily seized and can be sold on the international market at a significant mark up – to explain the onset and intensity of resource wars. Control over these goods motivates people to take up arms while the revenue from selling them fund the fight. Jeremy Weinstein shows how resource “rich” rebel movements are prone to attracting opportunists and thugs, who are ill-disciplined and prone to manhandling civilians. Rebel groups with access to lootable resources are liable to splinter and metastasize, becoming more like criminal operations than political movements.

But not all resources are lootable and not all lootable resources have the same centrifugal effects on rebel behavior. As Philippe Le Billon and Eric Nicholls have shown, unlike diamonds or drugs, dams and oil rigs are better targets for extortion than physical appropriation. After all, these structures are far more valuable assembled and operational than broken down for spare parts. Moreover, dams and rigs require a cadre of experts, technicians and engineers to run effectively. And, as Mancur Olson famously pointed out, opportunities for extortion create incentives for building sustainable, long-term rule, which are distinctly different from simply predation. According to New York Times reporter Thanassis Cambanis, IS  left the staff at the Tabqa Dam unharmed and in place, allowing the facility to continue operations and even selling electricity back to the Syrian government. Similarly, oil fields under IS  control continue to pump. Indeed, IS  has shrewdly managed these resources to help ensure a steady and sustainable stream of revenue. As one IS fighter told the New York Times, while Assad’s loyalists chant “Assad or burn the country,” IS retorts “We will burn Assad and keep the country.” Beside revenue from oil and water, IS  collects a variety of commercial taxes, including on trucks and cellphone towers. It has also imposed the jizya (poll tax) on Christian communities under its control. According to the Chaldean patriarch, so far there has been no violence committed against the significant Christian population around IS-controlled Mosul.

Whereas resources like diamonds or drugs motivate rebel forces to take as much as they can as quickly as they can, the need to manage capital and technology-intensive natural resources has actually increased the interdependence between IS and civilians. Already in effective control of significant amounts of oil and water, the Islamic State is one step closer to becoming a reality.

Most resource wars come to abrupt and violent ends, with the military defeat of one side. Macartan Humphrey suggests that external interventions are more common in resource wars in order to assert control over the spoils of war. Concomitantly, the availability of lootable resources is also corrosive to military discipline, making resource-dependent armies and rebels especially easy to defeat. When British troops intervened in Sierra Leone in 2000, the Revolutionary United Front was little but a collection of mafias fighting to retain control over the diamond mines and could mount little defense.

Yet IS appears to be the exception to this rule. Oil and water, unlike diamonds or drugs, contribute to the coherence to the Islamic State and the discipline of its governance. While both the United States and (even more significantly) Iran have dispatched military advisers to Iraq, full-blown outside intervention is difficult to imagine. Other forms of non-violent interventions, such as placing sanctions or embargoing IS’s oil production, are unlikely to be effective. Alternatively, coming to agreements on the disposition and distribution of water and oil resources could form the basis for some modes of negotiation. IS has already cooperated with the Assad regime in the distribution of electricity. While arrangements for sharing water and oil will not bridge the profound ethno-sectarian and ideological gap separating IS from the KRG, Iraq, Syria and the myriad of other belligerents, it could provide a basis for conflict management that mitigate the worst violence and spares civilians further harm.

Ariel I. Ahram (@ariel_ahram) is an assistant professor in Virginia Tech’s School of Public and International Affairs in Alexandria, Va. He is the author of “Proxy Warriors: The Rise and Fall of State Sponsored Militias (Stanford University Press, 2011).