Complete 6 pages APA formatted article: Realism, Liberalism and World System View of International Relations. At the same time, the historical development of these frameworks is presented and evaluated, at the level that it can explain their current form and role in IR. It is made clear that all three frameworks are critical for the evaluation of IR but it seems that not all of them are equally powerful in influencing key decisions related to IR. Realism and world system view of IR are based on rules, which are more aligned with the needs and the challenges of IR. on the other hand, liberalism is less involved in critical IR decisions since their core principles, which is the natural law which promotes morality, cannot support or tolerate the violation of human rights or other important values, in opposition with realism and world system view which leave space for such phenomena.In order to understand the differences between realism, liberalism and the world system of international relations (IR) it would be necessary to refer primarily to the context of these frameworks, i.e. their key principles, but also to their historical development.The theoretical basis of realism is highly related to Thucydides and his explanations on the political events developed during the Peloponnesian War (Korab-Karpowicz 2010, p.1). Emphasis should be given on the History of the Peloponnesian War as a text highlighting the key aspects of IR. In accordance with the above text, moral principles are irrelevant to international affairs (Korab-Karpowicz 2010, p.1). Through the centuries, realism has been developed using different criteria. The most critical example is the involvement of Machiavellian arguments (Ioana 2009, p.44) for explaining the role of realism in IR. Three are the key points of the above arguments: a) history is created through causes and effects (Ioana 2009, p.44), b) theory has resulted from practice and c) politics are not relevant to ethics (Ioana 2009). .