What is going on in Syria?

Syria is the first salvo in a war that puts Iran, China, and Russia against the US and its allies. The American government has thrown its weight behind the Sunnis, whereas Iran, China, and Russia are backing Bashar al-Assad, the Shi'a leader in Syria.
What's the difference between a Sunni and a Shiite, you ask?
A quick history lesson: not all Muslims are of the same cloth. Just as there are differences in the Christian faith – Protestants and Catholics – the two Muslim factions are the Sunnis and the Shiites.
The roots of the differences go back to the 7^thcentury CE, with the death of the prophet Muhammad. Those who accepted Abu Bakr, Muhammad's father-in-law, as caliph (successor) became known as the Sunnis. Those who believed that Ali, Muhammad’s son-in-law, should be caliph became the Shiites. From there, the differences grew, many battles ensued, and a schism formed between the two groups.
Why has the American government backed the Sunnis? Saudi Arabia is the short answer.
If a decisive Shiite victory were to occur in Syria, it would have implications throughout the Middle East, but most importantly in Saudi Arabia. Saudi Arabia's population and leadership are both Sunni. Mecca and Medina, two Islam holy cities, are situated in the country. The oil-producing areas of the country have significant Shi'a populations. If an uprising were to occur in response to Shiite success in Syria, Saudi Arabia's oil production, as well as economic, political, and social stability, could suffer a huge setback.
It is critical for both the US as well as the European Union that Saudi Arabia stay as it is to keep the balance of power intact in the Middle East. That's seen as a necessity for stability in the global oil markets. If Saudi Arabia's oil production were to stop, we could be looking at US$200 or more per barrel of oil immediately.
More important for the American government, if Saudi Arabia stays the way it is, the life of the petrodollar will be extended. Its fate is intertwined with the fate of Saudi Arabia; so when the people ask why the Americans spend so much on military might in the Middle East, the answer becomes clear. The actual cost of the US military presence is negligible when considered against the loss of the petrodollar – which would likely accelerate the demise of the US dollar as the world's reserve currency. The cost to Americans for almost everything would double overnight. Inflation would be wild, and the US economy would be crippled.

We are still a few battles away from the demise of the petrodollar, but it is critical for the US to have Syria fall. If it doesn't, this strengthens the Shiites in Saudi Arabia, which also strengthens the existing regime in Iran. Both of these outcomes are bad for the US government and its geopolitical interests.

                                                                                    Marin Katusa, CaseyResearch  7/3/13