In Early 1970s, after the collapse of Bretton Woods Gold standard, the U.S. struck a deal with Saudi Arabia to standardize oil prices in dollar terms. This means all the countries should buy the oil from gulf countries only through american dollars.
In return the U.S. would buy oil from Saudi Arabia and provide the kingdom military aid and equipment. The U.S. also agreed to provide the Saudis with weapons, and perhaps most importantly, guaranteed protection from Israel.
From the perspective of empire, this new “dollars for oil” system was much more preferred over the former “dollars for gold” system as its economic requirements were much less stringent.
This is the reason The U.S maintains a major military presence in much of the Persian Gulf region, including the following countries: Bahrain, Iraq, Kuwait, Oman, Qatar, Saudi Arabia, United Arab Emirates, Egypt, Israel, Jordan, and Yemen.
Below article may not be entirely true to my knowledge as I don’t have sufficient information to prove it, but it is believed that Petro Dollar system have a major role in it.
A very few of us know the inside story of why countries go to war. The most prominent energy wars being in Afghanistan, Iraq, Libya and Syria. After the Petro Dollar system was implemented certain international oil and gas companies wanted to build pipelines through their territory which the governments in these countries did not agree to.
2001 the US and the UK began their invasion of Afghanistan, called Operation Enduring Freedom and was successful in signing agreement with Turkmenistan and Pakistan for a gas pipeline through Afghanistan.
Destruction of Iraq & Libya
The destruction of the governments in Iraq and Libya arise from the fact that they both were planning to challenge the Petrodollar system itself by selling oil a currency other than the US dollar.In 2000, Saddam hit the main pillar of US hegemony, the dollar. He started to sell his oil in euros, instead of dollars. By 2002, Saddam had fully converted to a petroeuro – in essence, dumping the dollar. This is considered as one of the main reason George W. Bush announced the commencement of a full scale invasion of Iraq.
Like Saddam Hussein, Gaddafi had a plan to quit selling Libyan oil in U.S. dollars. He was going to insist that payment be made in a newly created gold-backed “dinar” which would be an African-wide currency to compete with the US currency, the dollar. Gaddafi’s Gold-money Plan Would Have Devastated Dollar. May be due to this reason French President Nicolas Sarkozy reportedly went so far as to call Libya a “threat” to the financial security of the world. The “Insiders” were apparently panicking over Gaddafi’s plan.
Energy wars in Syria
While Syria has significant reserves of oil, the main interest behind the proxy war fought by the US, the UK, Saudi Arabia, Qatar and Turkey against Syria is a pipeline you have probably never heard of. In 2009 the Assad government was asked to sign a proposed agreement with Qatar that would run the Arab Gas Pipeline from its North gas field through Saudi Arabia, Jordan, Syria and on to Turkey, with a view to supply European markets. But Syria refused instead the Assad government signed two deals with Iraq and Iran for oil and gas pipelines through Syria.In July 2011 Iranian officials announced a $10 billion gas pipeline deal between Syria, Iraq and Iran that would transport gas from Iran’s South Pars gas field, the world’s biggest, through Iraq to Syria. The Iran-Iraq-Syria gas pipeline plan was a “direct slap in the face” to Qatar, the Saudis and Turkey. This is one of reason that triggered some countries to remove the current government in Syria.
The major oil companies, the major US banks, and the US government are the only one who enjoy the Petro Dollar system and that’s how the US controls the world.