The First World War was a conflict that cost the lives of over 10 million people, devastated all of Europe and gave rise to modern warfare, as it is known Today. The Great War has been carefully examined and examined through many complex theories in order to understand how such a conflict turned into one of the most epic wars in history. This essay, like many previous works, seeks to examine the First World War and determine its causes through two distinct levels of analysis, individual and systemic. The individual level of analysis identifies the cause of conflicts in individual leaders or decision makers within a particular country, focusing on the characteristics of human decision making. The systemic level of analysis explains the cause of a conflict from a broad system level that includes all states, taking into account the distribution of power and interaction of states in the international system. I am trying to examine World War I from every level of analysis using a theory to explain the decision making of actors. I argue that, across the individual level of analysis, World War I was caused primarily by psychological explanations. Decision-makers in every state made mistakes when processing information and events, which forced leaders to develop biases and beliefs that pointed to war. While, at a systemic analysis level, the First World War was caused by the cult of the offensive. Each state believed that its offensive advantages were so great that a defending force would have no hope of repelling an attack, opting only for offensive military strategies. Through this examination I hope to explain why the First World War developed into the conflict it became and potentially how it could have been avoided. Finally, I also try to analyze this conflict from a modern perspective. Answer… middle of the paper… earn/gain land/property. The system only needed a small spark to light the wick. That spark was the Balkan region. The awarding of Sarajevo to the Austro-Hungarian Archduke Franz Ferdinand was all it took to plunge the European nations into war. The assassination led powerful nations to draw lines and provide unwavering support to their allies in the event of conflict. German support for Austria-Hungary provides a strong example of offensive-minded states exploiting the situation to instigate a clash between its enemies. The evidence that no nation made significant attempts to resolve the problem diplomatically and that the military was mobilizing before war was even declared demonstrates that an offensive-minded strategy was being implemented. The period before the July crisis is exemplary of how states were undoubtedly preparing for war..