Irrespective of the modern trappings of warfare—artillery, automatic weapons, captured armored vehicles, Kalashnikovs and rocket-propelled grenades—the playbook of ISIS is straight out of the seventh century. It has used the largely unguarded, ungoverned spaces of eastern Syria as a staging area to strike weakened areas of Iraq and Syria.

Many of the tactics and factors behind the success of ISIS are nearly identical to those detailed in the pages of The Great Arab Conquests, a 1963 work that chronicled the first wave of Arab conquest from 632 to 680, which swept out of the Arabian Peninsula, engulfing much of Asia and North Africa. The book’s author, Lt. General Sir John Bagot Glubb, also known as “Glubb Pasha,” led the Arab Legion of Transjordan, later Jordan, from 1939 to 1956.

With no infantry and only the most rudimentary tactics, Glubb pondered how a seventh century cavalry of illiterate goat and camel herders defeated the best standing armies. He attributed it, particularly in the dynamic early years, to four factors that combined religion and policy.

First, Islam was new and religious zeal was a driving force. Second, jihad—interpreted in this context as “holy war”— was a simple, unifying concept, and death through jihad promised instant entry into a paradise of carnal and other earthly pleasures mostly unknown in life. Third, leaders in Mecca and Medina mandated policies that allowed the armies to keep a fixed portion of plunder, returning the remainder to these two heartland cities. Plunder included women and fed a vast trade in concubines and other slaves. Fourth, all of the above created highly motivated warriors who, above all, were not afraid to die. Glubb observed that a soldier unafraid to die is a formidable adversary, hard to defeat.

In present day Iraq and Syria, anyone not subscribing to ISIS’s severe interpretation of Islam is an infidel meriting death or enslavement. Its genocidal murder and enslavement of Yazidis, Christians, Shiites, Kurds and resistant Sunni tribesmen is a tactic calculated to purge conquered territory, terrify its enemies, and enhance its jihadi credentials, to attract like-minded recruits.

Why anyone would be attracted to the ISIS Gotterdammerung of beheadings and mass executions mystifies most, but it is a potent attractant to a subset of disaffected Sunni Muslims looking for meaning in their lives and—perversely—seeking respect and dignity. The chimera of the Islamic Caliphate, the power of arms and the allure of the spoils of conquest are the ingredients of an intoxicating elixir.

ISIS will be defeated. It ruthlessly uses terror, light mechanized cavalry tactics and the interstice of governance resulting from geography and civil war to impose its chilling creed, but it has a short shelf life in the face of growing alarm and resistance in the Middle East and beyond.

Unfortunately, the disaffection of its adherents will remain long after its demise. ISIS is a symptom. The real cancer is the disaffection that fueled it—and that has no military cure.

The recent robust airstrikes against ISIS’s strongholds in Syria by a coalition of the United States and five Arab allies were a welcome signal that the gloves have come off. It was particularly encouraging that the Assad government was informed in advance that the strikes would occur and did not interfere, including in the U.S. strikes against the Khorasan Group, west of Aleppo.

While the news today brings much relief—someone is doing something—it is accompanied by handwringing that airstrikes alone are not enough, that ISIS will cleverly hide its military assets, and that only a combination of air power and ground troops can defeat ISIS on the battlefield.

All of that may be true, but it misses the point that an Arab coalition against ISIS—a coalition of countries that have been at odds and supporting various Islamic proxies in Syria—is a tectonic shift. Unwittingly, the rise of ISIS is the inflection point that may offer a resolution to the “wicked problem” that is Syria’s civil war.

Assad and his allies—Iran and Russia—surely recognize the reality that Syria is unlikely to soon be cobbled together again, if ever. Conversely, the U.S. and the regional powers must conclude that Assad’s departure from the areas his regime controls would leave a vacuum that would currently be filled by the likes of ISIS and Jabhat al-Nusra, risking the slaughter or expulsion of Syria’s Alawite, Druze, Christian, Shiite, other minorities and moderate Sunnis.

Assad has brutally protected his interests with mass murder, torture and starvation. He is a bad actor in a rough neighborhood of bad actors.

Yet the U.S.-led coalition and its allies need to order their priorities and use the much more dangerous threat of ISIS and the alignment of interests of Assad, Iran, Russia, the U.S.-led coalition, the Syrian “moderate opposition,” Iraq, Lebanon, Turkey and the West to support a negotiated truce between Assad and the moderate opposition. This would enable at least a coordinated effort against ISIS and Jabhat al-Nusra and an eventual negotiated settlement to end Syria’s misery.

None of this will be easy, and may well result in the Balkanization of Syria, which has de facto already occurred. But it may be the first, best chance to begin to bring and end to the civil war and get the regional powers to work together to seek a consensual, balance of power that will be to everyone’s benefit. It may not work and it may not last, but it is better than Syria’s bloody stalemate and the rampages of ISIS and Jabhat al-Nusra.

James Stephenson is a Senior Advisor at Creative Associates International