Realism has developed over centuries and is not a clear theory; it has been divided into structural realism and classical realism. Thucydides and Thomas Hobbes were the main initiators of the development of this theory, with their highly acclaimed works in The History of the Peloponnesian War (Thucydides 1974) and Hobbes's Leviathan (1981). In their work, they develop theories to explain human nature and how it inevitably leads us to war. Both discuss their opposing views on the principle of balance of power and how it can be used to explain conflicts between nations. In explaining the reasons for George W. Bush's invasion of Iraq in 2003, it is mainly Thucydides' theories that prove most useful, notably his idea that humans will always act in their own self-interest to establish power, and in this case also to gain resources. Although the two theorists' ideas differ, they both understand that war is inevitable. Say no to plagiarism. Get Custom Essay on “Why Violent Video Games Should Not Be Banned”?Get Original Essay Thucydides, a classical realist, argued that the most powerful state should strive to rule over other weak nations in his book, The History of the Peloponnesian War (Thucydides, 1974). In the post-Cold War world and after the fall of the Soviet Union, the United States remained unrivaled as the world's sole superpower. Bush was disgusted by Saddam Hussein's brutal dictatorial regime and sought to overthrow him to promote peace and democracy in the Middle East. However, in the post-9/11 climate, it is likely that Bush wanted to restore American power and expand its global influence, and to do this he believed this could be achieved by toppling Saddam Hussein. Thucydides had hypothesized that countries would always attempt to expand their global influence, and Bush saw Iraq as a starting point for domination of the entire Middle East. Iraq, North Korea, Iran and Syria were all countries included in the "Axis of Evil", which is why Bush invaded Iraq in the hope that there would be an effect domino if America succeeded in overthrowing the dictatorial regime of Saddam Hussein. Bush essentially hoped that these countries would feel outnumbered and adopt a democratic system under America's influence. Like Hobbes, Thucydides had a deeply pessimistic view of humans and asserted that they only acted in their own self-interest in order to establish power. Humans act out of “fear, desire for glory, and the pursuit of self-interest” (Thucydides 1974, pp. 73). Therefore, according to realist theory, this would explain claims that Bush invaded Iraq in order to seize its vast oil reserves for the benefit of his own economy, with increased global demand for a limited resource. Although the Iraq War caused hundreds of thousands of deaths, Thucydides and other classical realists would say that this would not matter to Bush since he was acting solely in his own self-interest. The balance of power theory in Thucydides' perspective can be explained as a circumstance in which the leading nation with the most power strives to reduce the power of its competitor. Bush sought to achieve maximum levels of power, a universal goal among countries, and also sought to preserve his own independence as well as that of all other nations (Mingst, K, A. and Snyder, JL 2017, p. 128) . )..