Cloaked in the ambition of the "war on terror" and buoyed by the unwavering post-9/11 support, the United States engaged in a bombing campaign in Iraq followed by an invasion in March 2003. In preparation for the 2003 invasion, the United States built a complicated case for war based on several problematic bodies of evidence and then presented this evidence to the American people and the international community; this disputed evidence was collected to justify the invasion of Iraq. The tenets of the case for war included: the connection of Saddam Hussein to the events of 9/11, the threat of weapons of mass destruction (WMD), and the unknown motives and future actions of an evil dictator. The United States is now over five years into the war, and the overarching sentiment among the American people is that the war in Iraq was based on faulty information and that "evidence" used to justify the war was either mostly unfounded or even fabricated.

Given this problematic evidence to support the official justifications for war, the research question is "Why did the United States still invade Iraq in March 2003?" Clearly, there is not a definitive answer to the research question. The variables for engaging in war are very complex. Often times the benefit of time passage will allow scholars to obtain a more focused understanding of "why" a sovereign power engaged in a particular war. We are not yet at a point where we can write definitively about "why" the US invaded Iraq in 2003. However, it is possible to present an analytical case regarding the reasons used in the time leading up to the US invasion of Iraq. In this thesis, the evidence has been explored, and the result is a presentation, an assessment of the evidence to make a case for why the US invaded Iraq.

Many different political opinions and theories have been advanced to explain why the United States entered this war. Several credible scholars and journalists have made meaningful contributions to the study of this war and the justifications used by the White House for it. It is possible to provide a preliminary framework for understanding why the United States invaded Iraq by using current events literature, official documents and other available sources to document the war in the absence of the official, classified documents. Based on an assessment of available evidence, this thesis proposes that one of the primary reasons for the US invasion of Iraq in 2003 centers on oil; the US was interested in protecting its oil interests and what the White House saw as US geo-strategic position in the Middle East.