Abstract: The Peloponnesian War is extremely significant in human history.Thucydides' record and analysis of the war attracted the attention of both historians and scholars of international relations.The former mostly try to get rid of the shackles of Thucydides' statement and draw a conclusion different from Thucydides by grasping and sorting out more details of pre-war history,while the latter mostly approve of Thucydides' judgment and attempts to further refine the "Thucydides Trap" from different perspectives.The reason for the difference is that historians regard the Peloponnesian War as an isolated event and the outbreak of the war as an accidental result of some butterfly effect.Scholars of international relations,however,view the outbreak of the War as an almost inevitable consequence of a certain phenomenon.The efforts of both fields in different directions are of great significance to our understanding of the outbreak of the Peloponnesian War.

Key words: Peloponnesian War, Thucydides, historian, scholars of international relations, causes of war