While observing the Middle East's perpetual, destructive turbulence, a Westerner easily and thus usually adopts an essentially bi-polar lens—allowing himself only two boxes into which all peoples, beliefs, movements, and events must be stuffed. Sometimes that bi-polar lens consists of Israel vs. everyone else. At other times, the lens pits Islam against the West, Arab against Jew, or Muslim against Christian. These generalities can help to depict broad trends, but underneath, there are significant factors that heavily influence both "sides" of a question. In reality, every corner of the Middle East has multiple sectarian divisions, and a bi-polar approach to interpreting current events can miss essential details.
We can see this in the events now playing out in Muslim areas of the Middle East. Westerners tend to put all Muslims in a single box as a unified front. The reality, though, is that Islam is as fractured and sectarian as both Judaism and this world's Christianity—perhaps even more so.
Islam has two main denominations: Sunni and Shi'a (or Shi'ite). Sunni Islam is by far the predominate form of Islam, accounting for some 85-90% of Muslims worldwide. The rest, roughly 10-15%, are Shi'a.
At their core, the theological differences between them boil down to who is the rightful successor to Muhammad, and thus who has had religious authority throughout history and today. The minority Shi'a believe in authoritative succession only through Muhammad's family. Thus, in order for a religious leader to be recognized, he must be able to trace his lineage back to Ali—Muhammad's cousin and the first male convert to Islam (the first convert was one of Muhammad's wives). Shi'a believe that Muhammad's family members were the most qualified teachers of Islam after him and the most trusted carriers of his traditions. Conversely, Sunnis, reject the claims of dynastic authority, instead holding that the Muslim community should elect its leaders. Thus, the interpretation of the Koran and the various sayings and traditions of Muhammad hangs on the issue of authority.
This Sunni/Shi'a schism has existed since Muhammad's death, and while they have not always been at open war, an undercurrent of tension has always existed. This sectarian division is a major factor in why the various Middle Eastern Muslim nations act and react as they do.
To add to the turmoil, numerous schools of thought exist within these two denominations. Within Sunni Islam is Wahhabism, a fundamentalist form predominant in Saudi Arabia, which at least partially influences Al Qaida, Hamas, and the Taliban. On the other end of the Sunni spectrum is Sufism, a mystic, esoteric—even Gnostic—form of Islam. Ramzan Kadyrov, the 29-year old Prime Minister of the Russian Republic of Chechnya, is Sufist—and has declared war on Wahhabism wherever it can be found, largely because the rebellious Chechen movement is Wahhabist.
These sectarian divisions are playing out in Iraq, Iran, Lebanon, Saudi Arabia, and Syria. Much of the unrest in Iraq since the fall of Saddam Hussein has resulted from these schisms rather than mere animosity toward Westerners. Under Hussein, a Sunni minority (under the Ba'ath party) ruled over the Shi'a majority with an iron fist. With the Sunnis out of power, the Shi'a are exacting their revenge through summarily executing Sunnis and bombing Sunni mosques—thus, the Sunnis have called for U.S. troops to remain in Iraq to help protect them from the Shi'a. The difficulty in forming an Iraqi government has centered on getting the Sunnis, Shi'a, and Kurds (an ethnic group spanning adjacent parts of Iran, Iraq, Syria, and Turkey) to agree on fair representation within the government. The Sunni minority holds the keys to the Iraqi insurgency, and it is unwilling to rein it in, as doing so would leave them politically powerless.
The Sunni/Shi'a division also appears in the Israeli-Hezbollah war. Hezbollah is a militant Shi'ite group given safe haven by Lebanon (itself a country fractured into Sunni, Shi'a, Druze, Maronite Christians, Melkite Catholic Christians, and Greek Orthodox). Hezbollah is supported by, and does the bidding of, Iran—a nation of Persian (not Arabic) peoples with a Shi'ite majority—and Syria—an Arab nation with a Shi'ite ruling class, sitting precariously on a Sunni majority. The same day Iran was supposed to decide on the international community's offer regarding its nuclear program, Iran-controlled Hezbollah made an incursion into Israel that succeeded in distracting everyone, momentarily, from the nuclear issue. Similarly, Iran wields tremendous influence with the Iraqi Shi'a, and is keenly interested in the shape the Iraqi government takes. It was a Sunni-led Iraq that attacked Iran with devastating consequences, and Iran will not willingly allow another Sunni-dominated Iraq to arise.
With regard to Sunni/Shi'a relations, Syria is in a tenuous position. As the Israel-Hezbollah war began, Israel made clear its reluctance to destabilize the al Assad government. If Syria were overthrown, chaos would ensue with no one in power to rein in the more radical (Sunni) elements. Israel would face a more dangerous and less predictable foe on its eastern border.
It is also instructive to note Arab reactions to the Hezbollah attacks. At a meeting of 18 Arab leaders, nearly half condemned Hezbollah—a bizarre occurrence given their normal penchant to condemn Israel whenever possible. One Sunni cleric in Saudi Arabia even went so far as to declare a fatwa (religious edict) against Hezbollah, condemning any Muslim who fought for it. In the Sunni world, Hezbollah's attacks are seen to threaten the status quo, largely because they represent an increasingly powerful Iran. While Arabs have no love for Israel, they also harbor grave concerns over Iran becoming a regional hegemon.
The Sunni/Shi'a division cannot explain everything—it, too, is a bi-polar lens with myriad irregularities and dynamics. Nevertheless, this powerful divide keeps the Middle East continually unstable. We cannot understand Islam, as it affects the Western world, without recognizing its fractured nature.