[The Persian Gulf has 55% of the world's oil reserves and 40% of its gas.]
Today Saudi troops fired on protesters in Bahrain. Bahrain is an island sheikdom in the Persian Gulf a mile off the coast of eastern Saudi Arabia. The majority of the people in Bahrain and most of the protesters are Shi'ites. The wealthy class and the royal family of Bahrain are Sunni.
The main Sunni power in the Persian Gulf is Saudi Arabia. The main Shi'ite power in the Gulf is Iran. The fighting in Bahrain can easily be seen as a struggle between Shi'ites and Sunnis. So can the fighting in Iraq. One is reminded of the Cold War when various countries and parties fought over seemingly local issues but in each case the underlying reality was that they were proxies for one side or the other.
In theory the endless Angolan civil war was between people who believed in socialism and anti-colonialism and people who believed in property rights and civil society. Behind one side was Cuban military and financial support and behind the other Portuguese military and financial support. But behind Cuba and Portugal were the Soviet Union and the United States.
During the Cold War it was not always clear whether the United States itself was a proxy for world capitalism and the Soviet Union for world socialism. Or the other way around. Even now it is not clear since the Soviet Union and world socialism, after long declines, collapsed simultaneously.
Similarly it is not clear whether Saudi power in the Gulf and Iranian power are proxies for Sunnism and Shi'ism respectively, or vice-versa. But it is beginning to look like it is becoming a wider conflict no matter how one looks at it.
Just as we use the expression 'World War' followed or preceded by a number to describe the catastrophes in Europe, we might do the same in the Middle East. The First Gulf War was the monster, fought from 1980 to 1988 between Sunni Iraq, then ruled by the lovable Saddam Hussein, and revolutionary Iran which had just overthrown the Shah, and ruled by the equally lovable Ayatollah Khomeini. It is estimated that Iraq lost 300,000 killed. 'Killed' mind you, not the vaguer 'killed and wounded' which is a military fact of the loss of effective troops. 'Killed' is human lives. Figures are less certain for Iran but the Wikipedia estimate is that 500,000 to one million were killed on the Iranian side. 800,000 to 1,300,000 killed altogether.
For comparison, in all the fighting, all the terrorism, and all the wars fought between Israel and its enemies over the past 100 years, the total number of dead on all sides is estimated at 51,000. More died in individual battles in the First Gulf War than that. While not specifically fought over religion, Gulf War I was nevertheless fought between a Sunni-controlled country and a Shi'ite country. Since Iraq was and is a majority Shi'ite country the export of the Iranian revolution to Iraq would have meant the overthrow of Sunni minority rule.
In 1990 Saddam Hussein invaded Kuwait. In 1991 the United States and its allies drove the Iraqis out of Kuwait. The Second Gulf War was a mere skirmish compared to its predecessor. Of the 959,000 coalition troops who participated, 396 were killed, 1,200 Kuwaitis died, and 20,000 to 35,000 Iraqis did not make it home. If one considers the almost 100 to 1 ratio between coalition deaths and Iraqi deaths, one sees the wisdom of the Marine Corps' unofficial motto, "Do not eff with the United States".
The Third Gulf War began in 2003 with the American invasion and occupation of Iraq. After a brief initial phase of American and British forces defeating the Iraqi army of Saddam Hussein, it soon degenerated into a long grinding civil war between minority Sunni forces unwilling to see an end to their centuries-old domination of Iraqi-Mesopotamian society, and Shi'ite forces supported by the United States.
Now with the transformation of the Third Gulf War into a Sunni - Shi'ite civil war in Iraq, it seems to be spreading into a Sunni - Shi'ite religious war all around the Persian Gulf. The Third Gulf War, currently a civil war in Iraq, seems likely to morph into the Fourth Gulf War, a prolonged conflict between Shi'ite Iran and Sunni Saudi Arabia.
What has just emerged in Bahrain, with Saudi troops firing into crowds of Bahraini protestors is a pattern of Sunnis shooting Shi'ites. This is just getting started and it can only get worse before it gets better.
And we, as Americans, are stuck with the morally and politically bankrupt but awash-in-oil Saudi regime as our ally.
Just for a sense of scale,
Egypt 80 million people
Iran 75 million
Iraq 31 million (about 20 million Shi'ite)
Saudi Arabia 27 million
Israel 7.5 million (about 5 million Jews)
Bahrain 0.8 million (about 0.5 million Shi'ite)
Just as an aside about how good an ally Saudi Arabia is to the United States. Muslims are not automatically anti-American and anti-Israel. The primary nexus between Islam and anti-American Islam, between Islam and terrorist fanaticism, between Islam and fanatic anti-Semitism and hatred of Israel, is the world-wide network of Wahhabi madrassas or religious schools. Which are entirely funded by Saudi Arabia.