It is becoming increasingly obvious that the crisis in the Middle East with respect to terrorism is spreading and will eventually reach Greece.

One critical factor is that the West cannot or does not want to understand that the greater problem is not so much ISIS, but rather the conflict between Shia and Sunni Islam.

A good example is the recent crisis in Yemen where the Houthi, a Shia minority, has taken over a significant part of the Sunni dominated country.

It is therefore not surprising that Saudi Arabia has committed hundreds of warplanes to Yemen and is about to launch a ground war against the Houthi in the name of Sunni Islam.

The same Saudi government in the past year has only offered to the U.S. coalition against ISIS a handful of planes and no troops.

The Sunni–Shia conflict, for the Saudi Royal Family, overshadows any threat posed by ISIS, al-Qaeda, or any other terrorist organization in the Middle East.

The only exception is an Iranian victory over ISIS, and the Saudi nightmare scenario that such a victory would lead to an Iraq dominated by Tehran.

That conflict has been going on since the death of Muhammad in the seventh century BC. Al-Qaeda and ISIS are opportunistic byproducts of this age-old war, and serve the religious and political ends of both sides.

Indeed, in Yemen it will not be unusual for the Saudis to work covertly with ISIS – from the perspective of Riyadh, it is much better for Yemen to be dominated by ISIS than a Shia minority.

The same rationale applies to Syria. The Saudis are not concerned that the Assad regime does not respect civil rights and is butchering its people – it is small beer for a country that maintains a religious oppressive regime that is only bested by the zealotry of ISIS.

Let us not forget that Saudi Arabia is a country that deprives women of all rights and legally treats them as chattel.

It is a country in which the religious police impose beatings, beheadings, and a variety of torture from transgressions as simple as drinking alcohol to cutting off limbs for stealing. The Saudis, in a given week, lop off more heads than ISIS in a month.

The Assad regime and its hangers-on are not Sunni Muslims but Alawites, an offshoot of Shia Islam that controls Syria at the expense of its Sunni majority.

The Saudis, as the leaders of Sunni Islam, are anxious for the demise of Assad and, to this end, have even supported ISIS affiliated organizations operating in Syria.

Indeed, the Shia-Sunni war overlays many of the smaller conflicts that continue to dog the Middle East. The Turks also desire a new government in Syria, but one that will take its marching orders from Ankara.

In as much as Saudi Arabia tries to maintain a religious hegemony over Sunni Muslims, the Turks have visions of a postmodern Ottoman Empire that would establish a political and economic hegemony over the Middle East.

Turkey, under the government of Recep Tayyip Erdogan, has been looking to the Middle rather than Europe – particularly as the economic crisis in the EU has made the prospect of Turkey joining the European Union less attractive for Ankara.

As America is slowly abandoning its interests in the Middle East, the Turks see an opportunity to fill the vacuum and dominate the region.

The only other competitor in the region is Iran. In addition to Tehran’s religious agenda, Iran is trying to reclaim its regional hegemony and beyond.

It has footholds in Lebanon and Syria, and now it may even have an ally in Yemen – a country next door to Saudi Arabia. Becoming a nuclear power is critical to the Iranian theocracy, since it will enable them to match not only Israel with respect to nuclear weapons, but give them prestige with which to impress their Middle East allies and competitors.

In this regional geopolitical context, terrorist organizations play a vital tactical role. Turkey, through ISIS, can check Kurdish ambitions towards statehood and continue to wear down the Assad regime.

For the Saudis, ISIS is a means at hand with which to check Tehran’s domination of Iraq and now a fifth column against the Houthi insurgents.

Ironically, ISIS also plays into Tehran’s schemes because the very threat of the terrorists against Iraq has given the Iranians an opportunity to defend the country and, in so doing, draw them into Iran’s sphere of influence.

It will be impossible in the future for any Iraqi government to force Iranian troops that are progressively moving into the country to leave.

For Europe, the problem of terrorism is going to be endemic and will spread from France and Germany, with large Muslim minorities, to countries like Greece (also with new Muslim minorities fleeing the Middle East), which are on the edge of becoming failed states.

Greece’s very poverty is a beacon for terrorist organizations to establish bases of operations and, from there, strike against richer targets. Tragically, the presence of terrorist networks will severely impact Greece’s last major industry – tourism.

Andre Gerolymatos is Director of the Stavros Niarchos Foundation Centre for Hellenic Studies at Simon Fraser University in Vancouver