Middle Eastern sectarianism has been present since the wars of succession immediately following the death of the prophet in the 7th century, though they've largely been stifled for the past century by colonialism and the repression of secular nationalist regimes in Egypt, Iraq, and Syria since the 1950s. The invasion of Iraq in 2003 had the unfortunate effect of allowing sectarian divides to spread and escalate into violence between Sunni and Shia militias, not contained within the country until the end of the decade. Unlike in Iraq, however, in Syria it seems sectarianism is a tool wielded by the government to combat the rebel forces.
Syria is presently the focal point for four major conflicts: the United States and its allies versus Iran and its allies, the West versus Russia and China, autocratic versus liberal governments, and now, more prevalent than before, Sunni vs. Shia. The recent appearance of Hezbollah, a Shia militia, in the streets of al-Qusayr, assisting Assad's military forces in the recapture of the city, demonstrates the Shias' growing primacy and is generating fears that the conflict will devolve into senseless, brutal sectarian violence. Though these fears are well founded (the 2006-7 sectarian episodes in Iraq stand as proof), they do not take into account other effects of the sectarian violence, notably the significant benefits generated for the government's forces. The Syrian regime's use of sectarianism to bolster its military strength is a brilliant geo-strategic move decades in the making, but also one that has the potential to expand beyond anyone's control.
Religion has been tapped by the Syrian regime as early as the 1970s, as a political tool to generate alliances and legitimacy. Bashar al-Assad's father, Hafez al-Assad, courted Shia religious leaders in Iran, Iraq, and Lebanon, offering them a place of safety, protection, and learning in a region of Damascus. In return, the Assad regime gained religious acceptance from their Shia brethren, as well as the opportunity to create important cultural connections with Iran and Lebanon. A region in Damascus, centered around the Shia Sayyida Zainab shrine, became a well-traveled hub, forming cross-cultural connections. Its significance to the Shia population has now been effectively harnessed by the Syrian regime to generate political and popular support for the counter-revolutionary war. Syria's use of the ties between the Shia populace against the largely Sunni revolutionaries is the result of an important strategic relationship, generated by the use of religious symbols and sectarian language.
On the other hand, sectarianism is an extremely volatile force and it may already be backfiring significantly for the Syrian government. The longer sectarian tensions persist, the greater the scale of the violence perpetrated. A gulf forms, created by strong feelings, language, and actions, that is more difficult to bridge with each passing day, signaling a prolonged, polarized, and highly destructive civil war.
Most significantly, it alters the purpose of the conflict beyond its initial cause. In 2011, the conflict began in protest of a dominant ruling family that happened to be of the Alawi faith, but this goal was steadily pushed aside by radicals on both sides. The government's description of the conflict as sectarian has persuaded the Alawite community that their only hope of survival rests on the success of the regime, creating an intractable zero-sum situation. Further, the regime has ensured, through brutality, that the opposition has a steady source of Sunni recruits to take up arms, while the rebels' rhetoric and actions have ensured have forced the Alawites to support Assad.
However, it is important to note that sectarianism is most prevalent in those areas of the country where there is significant fighting. Safety continues to take priority over religion in much of Syria. But, in those regions that see regular fighting, religious segregation is the norm, mistrust is omnipresent, and divides are forming that will remain long after the conflict ends.