Forecast

That a bloc of Shiite states has coalesced in the Middle East is a significant geopolitical development; that it is led by Iran means it could be short lived.

In fact, the bloc's formation and expansion, such as they are, were possible only through the division and weakness of Sunni Arab states.

Several factors, most notably the Syrian civil war and ethnic and religious constraints, will prevent Iran from projecting Shiite influence farther than it already has.

The sectarian conflict in the Middle East can neatly be divided into two sides: Sunnis and Shiites. Or so it would seem. The reality, it turns out, is more complicated. Sunni unity is a myth – the countries that constitute the Sunni camp are divided over a variety of issues. And the Shiites, whose power has grown since the early 1990s, nonetheless suffer from the inescapable constraints of being a minority population.

A Demographic Challenge

Indeed, the single most defining characteristic of the Shiite camp is that it comprises only a fraction of the Muslim population. More than three-fourths of all Muslims practice Sunni Islam.

According to a 2011 study by the Pew Research Center, only four countries have a Shiite majority: Iran, Azerbaijan, Bahrain and Iraq. But other countries have notable Shiite minority populations as well, including Yemen, Kuwait, Saudi Arabia, Afghanistan, Pakistan, Turkey, the United Arab Emirates, Qatar and Oman. Shiites also form the largest confessional group in Lebanon and account for as much as 20 percent of the 180 million or so Muslims in India.

Like their Sunni counterparts, the Shiites are internally diverse. Twelvers constitute the largest group, but there are many others, including the Ismailis, also known as the Seveners; the Zaidis, also known as the Fivers; the Alawites; and the Druze. All of these sub-sects differ geographically, linguistically, politically and ideologically.

Historically, the Shiites ruled only intermittently, with some notable exceptions. For example, the Fatimids maintained a caliphate, headquartered in Cairo and stretching from Morocco to the west coast of the Arabian Peninsula, from the early 10th century to the late 12th century. From 932-1055, the Persian Twelver Buyid Empire ruled much of what is now Iran and Iraq. Later, the Ilkhanate of the Central Asian Mongols governed over parts of Pakistan, Afghanistan, Iran, Iraq, Syria and Turkey. More recently, the Zaidis boasted an imamate in Yemen that lasted from 897 to 1962. Several minor medieval Muslim polities were also Shiite dynasties.

For the most part, however, instances of Shiite control were rare. Shiites were dominated by Sunnis until the 16th century, when the Safavid Empire designated Shiite Islam as its official religion. But by this time, much of the Middle East and South Asia had fallen under the control of either the Ottomans or the Mughals, both Sunni empires.

Establishing Footholds

Shiite power has since shifted to Persia. In 1979, the Iranian Revolution officially created a Shiite republic. Iran is now the largest and most militarily powerful Shiite country, and its power has enabled Tehran's clerics to support Shiite communities, and thus enhance its influence, in the Arab world. But expanding its influence was not always easy. Iran tried to leverage its own ethnic Azeris to use the Shiite majority in Azerbaijan to its advantage. However, until 1991, Azerbaijan was part of the Soviet Union and, as such, a secular nation. Its secularism, in turn, made it resilient to Shiite overtures.

Iranian influence has also been stifled in places such as South Asia. Strong states such as India and Pakistan, not to mention the war in Afghanistan, have made eastern expansion very difficult for Tehran. With its northwest and east largely closed off, the only other direction Iran could expand was west toward the Arab world. Despite the vicious fighting that occurred during the Iran-Iraq War in the early 1980s, Tehran was able to establish a foothold in Iraq made possible by the animosity between the regimes in Baghdad and Damascus. Indeed, Syria became an early Iranian ally, thanks in part to the fact that it had an Alawite regime ruling over a majority Sunni population. Syria's rulers also helped Iran develop Hezbollah into a major political and military force.

Two other events were instrumental to the expansion of Iran's regional clout: In 1989, the Iran-Iraq War ended, and, somewhat coincidentally, the Lebanese civil war was resolved. This left Hezbollah, Iran's proxy group, as Lebanon's single largest political entity. A few years later, Iraq invaded Kuwait, bringing forth the first Gulf War. For Iran, the war was incredibly beneficial because it weakened the government in Baghdad, which previously had protected the Gulf Cooperation Council from Iranian encroachment.

Subsequently, Iraq's minority Kurds and Shiites, whom Tehran had supported for years, began to exploit the growing weakness of the Iraq regime. By the time the United States defeated Saddam Hussein in 2003, Iraq was ripe to fall under Iranian control. And fall it did, giving Iran an arc of influence from Tehran to the Mediterranean Sea.

But Iranian expansion soon stopped, even if its aspirations for hegemony did not. Assuming its western flank was secure, Tehran saw an opportunity in the Arab Spring to expand into the Arabian Peninsula – the heartland of Iran's regional rival, Saudi Arabia. Specifically, Tehran hoped to use the Shiite uprisings in Bahrain to its advantage. Saudi Arabia, aided by its allies in the Gulf Cooperation Council, crushed the uprising and, by extension, Iran's hopes for gaining prominence in the island nation.

Soon thereafter, Iranian ambition was dealt another blow in Syria, where Arab Spring protests eventually evolved into full-scale civil war. The Alawite government is still intact, but its dissolution would be disastrous for Iran: It would cut Tehran off from its allies in Hezbollah and leave Iraqi Shiites exposed to a Sunni regime in Syria. It is little surprise, then, that Iran has supported the regime of Syrian President Bashar al Assad so enthusiastically.

Too Many Red Lines

Currently, Iran and the Shiites appear to be in better shape than Saudi Arabia and the Sunnis. Hezbollah and other militias have helped al Assad remain in power. The fight against extremist groups such as Jabhat al-Nusra and the Islamic State have given Iran time to regroup, as have the nuclear negotiations with the United States. Moreover, the Saudis have been preoccupied with the Houthi rebellion in Yemen.

However, the Shiites' advantages will not last. What gains the Shiites made largely came as a result of Sunni weakness and incoherence, and some recent developments suggest the Sunnis are regaining ground, if only temporarily. Rebels have gained critical territory in Syria, particularly in Idlib province, and Saudi Arabia and Turkey entered into an alliance to oust al Assad from power.

More important, there are simply more Sunnis than Shiites, and there is plenty of evidence to suggest Sunnis will not abide Shiite rule. In Lebanon, Hezbollah has been unable to dominate the government, despite the size and influence of the militant group. In Yemen, the Zaidi movement may emerge as the Yemeni version of Hezbollah, but it cannot impose its will on the country beyond the core Zaidi areas. In Iraq, the Islamic State is still a powerful Sunni group, even in areas dominated by Shiites, despite its barbarity.

Jihadists do, in fact, threaten Iran and its Shiite allies, but they also represent an opportunity. Jihadism weakens Sunni states and tends to swing international opinion toward Iran. The Iranians are hoping that Saudi Arabia will buckle; from their perspective, the momentum of the Houthi movement in Yemen could help trigger a similar uprising among the Ismailis in the Saudi provinces of Jizan and Najran, both of which abut Yemen. Ideally, the Twelver community in Saudi Arabia's Eastern Province would flourish – a development that, along with Bahrain, could create an important outpost of Iranian influence in Saudi Arabia.

There are simply too many red lines for the region's Sunnis. Even in the unlikely scenario that Saudi Arabia weakens so much that Iran assumes de facto control of the Arabian Peninsula, the Sunni populations would not allow the holy cities of Mecca and Medina to remain under Shiite control. And there are simply not enough Shiites to do anything about it since they are essentially surrounded by Sunnis.

In addition to religious considerations, there are also ethnic considerations that prevent the spread of Shiite rule. Shiite leadership is now in the hands of Persians, not Arabs. And though Arab Shiites have aligned with Tehran, they have done so only out of necessity, maligned as they are in their respective countries. This limits the extent to which Iran can rely on them to serve its purposes.

Though the Shiites of the Arab world have largely united, some of their differences will be very difficult to ignore. Competition still exists between the Iraqi theological centers of the Arab-dominated Najaf school and the school in Qom, and Tehran has tried hard to increase its influence over Najaf. Iranian leaders hope that the power vacuum in Iraq will enable them to spread their doctrine of Velayat-e-Faqih. But with Iran undergoing its own political transformation, tensions between liberal and conservative factions – and between democratic and theocratic factions, considering the rise of Iranian President Hassan Rouhani and the domestic rehabilitation he began – have become more acute. Those tensions could well command Iran's attention, leaving its international aspirations by the wayside.

Thus, as much as Iran would like to further exploit current Sunni weaknesses, changes underway in Tehran could thwart its leaders' regional ambitions – as could internal differences among Shiites and the progression of the Syrian civil war.

Lead Analyst: Kamran Bokhari