International war, as part of International Relations, can be defined as conflict among states, and it has existed since human beings appeared on the earth. Whether this conflict or diplomacy among states, international interactions are described by two schools of thought, Realism and Liberalism. Realism explains international relations in terms of power, where states are the most important actors, they act as rational actors in obtaining own their interests in the short-term, and act within an international anarchic system (Goldstein 71, 72, 111). In contrast, liberalism criticizes realism, saying that power using military force does not seem all-important as a form of leverage, that rationality should seek to share in long-term collective benefits, and the world has distributed power (Goldstein 115-118). Currently, we are in conflict with Iraq and there is controversy among scholars, realist and liberalist, about invasion of Iraq.