Graham Allison introduced the concept of Thucydides's Trap to describe the current Sino-USrelations and attributed the war between Athens and Sparta to the challenge of the emerging power against theestablished power, thus inferring that the outbreak of war between the rising China and US as the leader inthe world is a high probability event. However, looking back to Thucydides 's description of the war betweenthe two sides in the History of the Peloponnesian War, it seems that the analogy between the two sides wouldbe inappropriate to apply to the prediction of Sino-US relations. The Thucydides's Trap is essentially amisunderstanding of Thucydides by Allison, which misleads international public opinion to a certain extent, thusforming a new cognitive trap-the Allison's Trap, to interpret pessimistically Sino-US relations. The fallaciesare: the Peloponnesian War was caused by the overexpansion of Athens, instead of its rise; the contrastingpattern of powers is not the decisive factor in the outbreak of war; the relationship of China and the UnitedStates can't be compared with that of Athens and Sparta. Therefore, the enlightenments of the History of thePeloponnesian War on China 's diplomatic strategy toward the United States lie in: persisting in the peaceful rise andavoiding excessive expansion; properly handling the fear of the defending country in the face of a rising country.