It was obvious several years ago, when Mahmoud Ahmadinejad was Iran’s president and the Islamic Republic was expanding its power in Iraq, Lebanon, the Palestinian areas and Yemen, that this endeavor would provoke a backlash from the Sunni Arab states.

And it was just as clear that this backlash, to compensate for Iran’s demographic and military superiority, would be primarily sectarian in nature. Today, we are living through the sectarian response to Iran’s sectarian strategy throughout the region. The potential consequences are frightening, and we are already seeing the precursors of this in Syria, Iraq and Lebanon.

There has been much debate over whether the Islamic State of Iraq and Greater Syria (ISIS) represents a majority of Sunnis, particularly in Iraq. The question is naïve. ISIS almost certainly does not represent most Sunnis, but nor did the Bolsheviks in 1917 Russia. Vanguard movements are not often democratic in nature. They seize the initiative during periods of social and political vacuum, rapidly mobilize supporters against established orders and, before anyone has had time to react, create dynamics in their own favor before systematically eliminating their rivals.

The Iranians should know this more than anybody else, since that is how Ayatollah Ruhollah Khomeini came to power and ultimately consolidated his authority after the revolution. And it is what ISIS is doing today in Iraq, this week having started to arrest Saddam-era Sunni military officers in Mosul, in order to ensure that no political counterweight can emerge.

In Iraq, Syria and Lebanon, Iran bolstered Shiite or Alawite regimes or parties that sought as best they could to marginalize the Sunni community. This has now blown up in Tehran’s face. Iraq is breaking apart, Syria’s regime is pursuing an active policy of partition and Hezbollah is facing an increasingly dangerous Sunni challenge in Lebanon that it will not be able to contain. Only in Yemen are Iran’s favorites making headway, and even then, for every action there is usually an equal counterreaction.

The Lebanese situation is especially alarming. While most of Lebanon’s Sunnis have no patience for ISIS, they are caught between two very disturbing realities: The absence of a moderate leadership on the ground that can contain the more radical elements in the street; and a perception among many in the community that the regional sectarian tide is turning, so that the million and a half Syrian refugees in the country, most of them Sunnis, are regarded as a welcome addition in the perceived struggle with Hezbollah and the Shiites.

This is extremely worrisome, because if Lebanon’s Sunnis are pushed in a direction where extremists impose on them an abandonment of coexistence, the country will be finished.

Should Sunnis come to be dominated by their radicals, sectarian dynamics will once again kick in. Lebanon’s Christians and Shiites will almost certainly move closer together in a shared reflex of self-preservation. Those Sunnis who are happy today with the Syrian refugee presence should beware: In 1975 the community took a similar attitude toward the Palestinians, and, similarly, regarded the Lebanese Army as doing the work of its political foes. The results, as we know, were calamitous.

But Hezbollah is hardly innocent. For years the party was warned that its reckless policies and acts of intimidation after the Syrian withdrawal in 2005 would only exacerbate sectarian relations. But it was all hubris from Hezbollah, culminating in the party’s military takeover of western Beirut and its attacks in the mountains against the Druze in May 2008. Hezbollah continued on this path long afterward, entering the Syrian conflict to help Bashar Assad’s regime crush a mainly Sunni uprising, helping to import the Syrian war into Lebanon.

The Sunni genie is out of the bottle, and there is little Hezbollah can do about it. The party is too involved in Syria on behalf of its Iranian sponsors. Even in the ongoing war in Gaza, Hezbollah hardly qualifies as an afterthought, as Hamas and Islamic Jihad show Tehran what they can do with its rockets.

What does this tell us about Iran’s hubris? The Mideast is a graveyard for grand projects of hegemony, and if America failed we shouldn’t be surprised that Iran is doing the same. The Islamic Republic backed the maximalist, sectarian policies of Prime Minister Nouri al-Maliki in Iraq and Assad in Syria, precipitating the disintegration of both countries. Iran, too, is multisectarian and multiethic and may not be shielded from the aftershocks.

It’s easy to believe in a cataclysmic scenario for the region. What makes one so conceivable is the fact that sectarian animosities are grafted onto a body of failed Arab states, where democracy, economic development and any redeeming sense of personal and social amelioration have been frustrated for decades. There seems to be no way to resolve differences except through repression of the other. And on those rare occasions when conciliatory policies might have been adopted and sectarian coexistence reinforced, precisely the opposite was done.

The so-called Arab Spring broke the back of the old order of supposedly secular dictatorships, but failed to bridge the gap toward more democratic and pluralistic entities. Today we are caught in a political no-man’s land – with neither the security offered by the dictators nor the representativeness of pluralistic systems.

The Middle East is at a foundational moment in its history, one perhaps more momentous than the post-World War I period when the region’s contours were redrawn. The optimists will say that all change brings something better. But until that time it will bring a great deal that is worse, as regional states come to the realization that their arrogance and irresponsibility has released forces with the potential of devouring them.