This chapter examines the effect of George W Bush and Tony Blair’s leadership styles on the decision-making process that led to the invasion of Iraq. More than perhaps any other US and UK military action of the past twenty years, the Iraq War is associated with the individual leaders of the two nations. Despite the differences in the systems in which they operated, both Bush and Blair’s leadership styles were very influential in this decision-making process. This chapter combines three measures of leadership style to analyse Bush and Blair, scrutinising their conceptual complexity, approach to risk, and management of their advisory systems. Firstly, Bush and Blair were very similar in their black-and-white worldview, which stemmed from their low conceptual complexity. Secondly, both leaders typically proceeded despite the risks that they perceived in the decision-making process, with little change in the way they proceeded. Blair faced greater restrictions on his actions, and as such, he also confronted greater risks in the process of deciding to invade Iraq. Yet, again, despite the differences in the systems they operated, both Bush and Blair were very willing to confront these risks. Thirdly, both leaders managed their advisory systems in a manner dictated by their low conceptual complexity. Both leaders organised their advisory system to prioritise advice that agreed with their previously held views, further complementing the actions of the mindguards and exacerbating the impact of Groupthink. Alongside providing key insights into the actions of the two men most associated with the invasion of Iraq, this chapter illustrates the key links between the explanations of each individual model, demonstrating why using these models in conjunction is so efficacious.