Islamic civilization is unstable and unsustainable.

Daniel Greenfield, a Shillman Journalism Fellow at the Freedom Center, is a New York writer focusing on radical Islam.

Islamic violence is nearly impossible to deny. But why is Islam violent? The usual answer is to point to Koranic verses calling for the conquest and subjugation of non-Muslims. That certainly covers the theological basis for Islamic violence. But it fails to explain why Muslims continue to practice it. Even against each other. Violence has become the defining form of Islamic exceptionalism.

Optimists speak of reforming Islam. But such reforms had over a thousand years in which to take place.

Islam is an ideology. Its violence is a strategy. That strategy fit the needs of Mohammed. Mohammed chose to use force to spread his ideology. He needed to recruit fighters so he preached the inferiority of non-Muslims, the obligation for Muslims to conquer non-Muslims and the right of his fighters to seize the property and wives of non-Muslims as incentive for them to join his fight. Furthermore he even promised them that if they should fall in battle, they would receive loot and women in paradise.

The strategy was barbarous, but quite effective. Mohammed had created a new super-tribe in a tribal society. The tribe of Islam united different groups in a mission of conquest. The Islamic religion allowed the varying clans to be more effective and ambitious than their victims. Within a surprisingly short amount of time the chain of conquests made Islam into a world religion. The most effective Islamic conquerors could not only claim vast territories, carving up civilization into fiefdoms, but they could prepare their sons and grandsons to continue the chain of conquests.

Islam made the standard tactics of tribal warfare far more effective. Its alliance was harder to fragment and its fighters were not afraid of death. But at the same time Islam remained fundamentally tribal. It made tribal banditry more effective, but didn’t change the civilization. It codified the tribal suspicion of outsiders and women into a religious doctrine. That still drives Islamic violence against non-Muslims and women today.

And yet Islam could have reformed. All it had to do was choose a different civilizational strategy.

The current clash of civilizations is between cooperative societies and hierarchal tribal societies. Western countries are cooperative societies. They succeed by bringing together a variety of peoples into cooperative organizations. These organizations negotiate and exchange everything from goods to mutual defense. Primitive versions of such organizations existed in Mohammed’s time. They have also existed within Islamic societies, but they have been inhibited by the tribal instability of Islamic civilizations. Cooperative societies emphasize internal conscience over external posturing. Religion is a matter of personal morality, rather than collective conquest. Economic resources are developed by harnessing new ideas and techniques to provide wider benefits to the society.

Islamic tribal societies are governed by extended family groups and other hierarchies that, like Islam, serve a similar role. While such societies can be locally stable, albeit backward, expanding them is difficult because their only point of unity comes through conflict with outsiders. Without external conflicts with non-Muslims, tribal societies degenerate into internal tribal conflicts.

That is what happened in Iraq and Syria, not to mention Yemen and Libya. Most Muslim countries are delicately balanced on the edge of a precipice and they can be very easily tipped into horrifying violence between different groups if their fragile internal order breaks down and there are no outside enemies.

The Muslim expansion became unsustainable once the external spread of conquest limited the access of Muslim armies to non-Muslim victims. Islamic unity did not survive Mohammed for very long. Stability came through feudal societies which were slow, backward and unwieldy, but prevented conflict.

Ultimately the only stable Muslim society is a slave state. Modern dictatorships, which strive to imitate modern countries by building up professional elites of doctors, engineers, lawyers and generals, are eventually undone by them. It’s the genuinely backward kingdoms that rely on oil wealth and slave labor which best weathered the changes of the past generations and maintained their ruling privileges.

And here we come to the fundamental crisis of Islamic violence.

Islamic civilization is fundamentally unstable and unsustainable. Contact with the modern world destabilized it setting off a series of chain reactions. Islamic civilization, particularly in the Middle East, could not make the transition to modernity. Those countries that had oil could buy their way out of the problem with generous subsidies at home while purchasing influence abroad. The Saudis made their own people rich while controlling the West. They financed wars without needing generals by funding terrorists. They kept a tribal society going by hiring foreign professionals to do most of the technical work.

Most Muslim countries however couldn’t buy that type of immunity from modernity. And even the Saudis had only bought a temporary immunity that is running down along with oil prices. The most Islamic societies had followed the old Mohammedan practice of exhausting the land. But where were they going to move on to?

The mass migration to Europe is part of the answer. While Europeans are shocked at the sight of millions of people just picking up and walking away, the Middle East still has deep nomadic roots. Most Muslim countries are political and historical fictions. Family groups matter far more than national identities.

Outside Israel, agriculture in the Middle East is sparse. The strong attachment to the land that is found among Israelis or Europeans is absent. Feudalism associates working the land with inferiority and feudalism is a more recent memory among Muslims than among most Europeans. Success means expanding into someone else’s land and living off the spoils rather than staying and working your own.

Western cooperative societies eagerly welcome Muslim migrants because they expect them to cooperate and contribute. But that is not happening. Muslim societies are hierarchical, not cooperative. The new arrivals expect to fit into a hierarchy. If they don’t encounter a strict hierarchy, they seek to “conquer” by establishing their hierarchy with the supremacism of the Koran as their guide.

Western societies seek to settle permanently. They plan for the long term. Nomadic tribals burn through resources, viewing cities and institutions as assets to strip, raid and dispose of, before moving on. The Islamic migration is not a new phenomenon and Europe is not meant to be its stopping point.

This is a variation of Mohammed’s old strategy. While some Islamic groups, such as ISIS and Al Qaeda, stay behind to battle for the dying lands of the Middle East to establish their own perfect society, large numbers of Muslims are choosing to move on to fresher pastures. This cycle will only repeat itself.

This strategy is why Islam continues to be violent. It’s why exporting democracy is useless.

Democracy works in cooperative societies. It can only work within tribal societies as a democracy of groups. And it requires that these groups prefer cooperation to conflict as a civilizational strategy.

Islam favors conflict over cooperation. In the absence of outside enemies, its doctrine allows its quarreling groups to name each other as infidels, heretics and enemies. To reform Islam, Muslims would have to make the civilizational transition to a cooperative strategy. They would have to fundamentally change their values, their priorities and how their societies function.

And there is no sign of that happening.

Islamic civilization becomes unstable once it expands beyond its tribal limits. Its only coping strategy for that instability is violence, whether directed externally at non-Muslims or internally at other Muslims. Its economic development tools are limited and make supporting a modern society very difficult because they emphasize maintaining internal hierarchical stability over innovation and progress.

Islam is violent because it’s unstable. Its only tool is violence. Its societies exhaust their limited resources and then invade their neighbors. They repeat the same strategy until they are stopped. Then the exhausted Islamic civilization becomes a staid slave society that is stable, but backward. If that society is disturbed, then the egg cracks and the whole horrible process of war, invasion and exhaustion begins again. That is what we are experiencing right now. And there is no easy answer to this problem.

We can inhibit the expansion of Islamic migration. Or it will wash over our societies and destroy them.