system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What's going on in Syria?

I've had others try and explain this to me, but not well, and I feel like it's pretty fucked up how little I know about such a massive issue. So please: wtf is going on in Syria?
gpt
The country has been ruled for decades by a military dictatorship run by a minority Islamic sect, the Alawites. Up until fairly recently, they've been brutal and repressive, but not especially incompetent. One of their chief advantages is that the substantial Christian minorities of Syria have backed them, because they feel that if a regime representing the large Sunni Muslim majority takes over, the Christians are going to become oppressed the way they are in Egypt. Also, the regime receives substantial support from Shi'ite Iran, who wants to counterbalance the Sunni regimes in the rest of the Middle East, and from China and especially Russia, for various geopolitical reasons.

Dictator Hafez al-Asad died in 2000. The son who was the heir apparent was killed in a car crash, so second son and weak-chinned douchebag Bashshar, who went to medical school in London, is given the job. For most of the 2000s, he tries to implement some gradual and mostly token reforms. 

Fast-forward to 2011 Arab Spring protests. Syrian government badly overreacts to these, killing protestors in ways guaranteed to inflame the mushy middle. They're especially bad toward journalists, and Sunni-run Al Jazeera takes great glee in endlessly replaying shitty cell-phone videos of Syrian troops doing awful things to first civilian protestors, then rebel soldiers. Country's Internet is cut off. Hundreds of thousands flee, mostly to Turkey, who for historical reasons doesn't much care for the Syrian regime.

Now the rebel armies show up. They're made up of civilians who've just had enough, Syrian defectors, and jihadists [not many at all at first, but significantly more as time has passed] from the worst corners of the world. At first, they're all about liberalizing and freeing Syria; soon, they become all about jihad and imposing Salafist (ie, Muslim fundamentalist) ideas on the country. Many Christians and urban liberals begin to have second thoughts, but it's too late. The regime troops have no qualms at all about killing non-combatants, and the rebels none about summarily executing anyone suspected of collaborating with the regime.

The country has been effectively destroyed by the fighting. Asad is losing, but slowly, and he's going down fighting. US intervention is problematic because a) Syria is much more heavily armed, especially with air defenses, than Libya was; b) it's not like the rebels are really the good guys either; c) Syria's state sponsors, specifically Iran and Russia, will make way more trouble than anyone would have about Libya, where everyone realized Qadhdhafi was an evil nutcase who had no friends. Oh, and d) Syria has no oil and Libya has shitloads.

So expect a horrifying, entrenched civil war to continue on for another year or two until the rebels get lucky and take out Asad. Then expect years of sectarian turmoil as anyone not willing to bow to Salafism gets killed or exiled. Then another military dictatorship, this time with extra added k-k-k-krazy fundamentalist Islam. 

Nothing good will come of it for at least 20 years.

Edited to add the bracketed material for clarification.