By scrutinising the Bush Administration's rationale for war and examining a variety of possible objectives that are based on constructivist concepts, I will try to make sense of this war which remained unexplainable to many other international relations (IR) theories. In a first step, I will give a brief introduction to Constructivist theory focusing on the three principal aspects of state identities and interests, international structure, and conditions of cooperation and conflict. Secondly, I will address the issue of America's threat perceptions and enemy images in order to explain how inherited values and attitudes shaped the Bush Administration's assessment of the incident. Following a description of the US rationale for war, I will focus on the theme of international normative frameworks so as to explain why they imposed their decision against the serious concerns of the UN community of states. In this context, an important role will be played by the substantial unilateral freedom of action gained by their hegemonic position in the international system. Finally, I will return to the point of US identity in order to specify that the invasion of Iraq might have made little sense from a rational point of view because it harmed European-American relations in the long term and aggravated international tensions, but that it nevertheless conformed to the imperialist ambitions of US exceptionalism and their historically defined claim to leadership.