The "petrodollar" is a term coined to describe the system by which oil (petroleum) is priced and traded worldwide in U.S. dollars. This system arose in the 1970s when the U.S. negotiated with Saudi Arabia and other OPEC nations to sell their oil exclusively in U.S. dollars. In return, the U.S. offered protection and support. This arrangement had several benefits for the U.S., including creating a consistent, high demand for the dollar, which helped maintain its status as the world's reserve currency.
Saddam Hussein, the late President of Iraq, made a decision in the year 2000 that sent ripples through this system. He announced that Iraq would start selling its oil in euros, not dollars. If other countries followed suit, it could have potentially weakened the U.S. dollar's global dominance. However, Iraq was not the biggest oil exporter, and this move did not immediately result in a widespread shift away from the petrodollar system.
Saddam's decision has been linked by 9/11 theorists to the U.S.'s 2003 invasion of Iraq, suggesting that the switch to euro pricing was the real reason for the war, as opposed to the stated reason of Iraq's alleged possession of weapons of mass destruction. Critics of this theory point out that there is no substantial evidence to support it, and it fails to adequately explain the complex political, strategic, and economic factors that led to the Iraq War.
Following the U.S.'s occupation of Iraq, the country's oil sales were switched back to the U.S. dollar. While this did align with the interests of the U.S. and the petrodollar system, whether it was a primary motivation for the invasion remains a topic of speculation and debate.
It's worth noting that the petrodollar system has been facing growing challenges in recent years. Several countries, including China and Russia, have made moves to trade oil in their own currencies or in alternatives to the U.S. dollar. However, as of my knowledge cutoff in September 2021, the U.S. dollar still remained the dominant currency for global oil trade.
While Saddam Hussein's decision to price Iraq's oil in euros was a notable deviation from the petrodollar system, the evidence supporting claims that this decision was a primary cause of the U.S.'s invasion of Iraq is tenuous at best. It is important to approach such theories with a critical eye and a demand for robust, substantive evidence.