Iran is the heart and soul of Team Shia. Unlike Team Sunni, the Shia team is comparatively monolithic — or at least doesn't break into large, powerful factions who are at each other's throats. While the Shia have been a long-established flavor of Islam, the modern story of the Shia really takes off in 1979 with the Iranian Revolution.
In the interests of avoiding a multi-volume series on all the screwed-up and confusing things that have happened in the Middle East since 1979, let's note one thing and then skip ahead. During and immediately after the revolution, Iran really made a big deal of being an Islamic Republic, full of rule according to the Koran with all manner of theocratic trimmings.One of the main ways that it attempted to make that branding stick was claiming that it was not only super Islamic, but was also saving Islam from its natural enemies Israel, the US, and the decadent West as a whole (and sometimes also the Soviet Union for good measure). Even to this day, 35 years later, "Death to America" is a fundamental ideological tenet of the revolution and crops up in every Friday prayer.
It's safe to say that opposition to the US is still major part of Iran's marketing brand as the most authentic flavor of Islam going.
Fast forward to today. Until recently, Iran was pretty happy fomenting rebellion and aiding Shia insurgents in otherwise nominally Sunni countries like Yemen and Bahrain. That was until the Arab Spring caught fire in Syria, turned that country into a morass of death and violence, and Iran found itself supporting the Syrian government. Syria has long been one of Iran's closest regional allies, because it is firmly anti-US, implacably hostile to Israel, and is run by the more-or-less Shia Alawaite sect.That ugly war has been dragging on for a couple of years now. Iran has been backing Syria by pushing Hezbollah (the Iranian proxy in Lebanon) to send fighters, directly supplying the regime with money and weapons, and even sending its own troops to battle it out against both factions of Team Sunni (the establishment "good" Sunnis and the extremist "bad" Sunnis). Fighting in Syria has been essentially stalemated. The only folks who seem to be doing well are extremists who have effectively turned the Syrian battlefield into a Graduate School of Hard Knocks for Islamic fundamentalists with a penchant for violence. As a side note, countries all around the world will be reaping the bloody harvest of this particular phenomenon for decades to come. Right now, Syria is doing for future terrorists what Afghanistan did decades ago, but on a bigger scale.
The only folks who seem to be doing well are extremists who have turned Syria into a Graduate School of Hard Knocks for Islamic fundamentalists with a penchant for violence.
While there's a lot of talk about what the US is or isn't doing, the practical effect of these players right now may be pretty limited. It turns out that after all the domestic political opposition to the last decade of fighting in Iraq, the Western allies are a wee bit gun shy about getting dragged into more Middle East fighting. While there is certainly some proprietary interest and desire to avoid writing off the meager gains that were made in Iraq, the disinterest in more casualties trumps that.
Where this gets to be a problem is that nobody (outside of Team Sunni Extreme) is enthralled about creating a great big Team Sunni Extreme home base a.k.a. the caliphate. If Iraq breaks up, it doesn't mean the fighting will end — it just means that it will look a lot more like internal ethnic cleansing and genocide than a battle for control over the country, and the caliphate's battle for creation will be half won. The US and West also really don't like the idea of breaking up Iraq, in part because it opens the door for the Great Middle Eastern "Clarification." This is the possible decades-long ugly battle to sort out a century or more of ethnic, sectarian, political, and economic tensions that have been locked in place throughout the region.There's an outside chance that Team Iraq might get a reprieve in the form of a new prime minister. If Iraq can pick someone who is intent on forging a real national coalition government, who can hold the country together in the interim, and who can do this without alienating any would-be foreign support, then things look a lot better for Team Iraq. But that's a mighty tall order and until then Western support most likely won't rise to the level of making sure Iraq wins, but merely making a visible effort to prevent Iraq from losing.
The dirty little secret here is that in this fight, the US doesn't have to do very much at all to prevent Iraq from being overrun entirely.