The argument the United States made for invading Iraq in 2003 was that reports indicated that Iraq was stockpiling weapons of mass destruction. This claim was a major factor used to justify the invasion. The U.S. government argued that Iraq's possession of such weapons posed a threat to the region and potentially to the United States and its allies. However, after the invasion, no substantial evidence of these weapons was found, leading to significant controversy and debate about the decision to go to war.
It is important to note that the other options provided in the question were not the primary justifications used for the invasion of Iraq in 2003. While Saddam Hussein's regime was accused of various human rights violations and had historical tensions with the U.S., the main argument put forward at that time centered around the alleged presence of weapons of mass destruction in Iraq.
