wrong in assuming that unipolarity leads to a stable order. He argues that it is the contestation that compels the great power and other states to build international order. Maria Gavris has criticized HST for its underdeveloped conceptualization of hegemony. Post-Cold War period Theory On the "unipolar moment" in 1990, the leading expert on the world-systems theory, Christopher Chase-Dunn, linked the forthcoming period with the HST. He reminded that hegemonic rivalry led to World Wars and in future such a rivalry among core states is only likely if the US hegemony continues to decline. But the current situation of single superpower is eminently stable. To the mainstream International Relations (IR below), the unipolar world came as a surprise. Reailists, shaped by “two World Wars and the Cold War, understood the differing logics of multipolar and bipolar systems, but apparently failed to envision a unipolar world because none of their works before the end of the Cold War accounts for it.” For several more years following the “unipolar moment,” IR analysis overwhelmingly argued for instability and imminent collapse of the hegemonic order. Mark Sheetz was one of the first IR scholars to explicitly link the post-Cold War order with the HST: The US strategy, he wrote in 1997, fits “the expectations of hegemonic stability theory more comfortably than do other Realist theories. The latter predict that efforts to preserve hegemony would be futile and counterproductive, but “not so hegemonic stability theory.” Only in 1999, came to light an article completely and explicitly devoted to the subject.William Wohlforth titled it “The stability of a unipolar world,” paraphrasing the 1964 title, “The stability of a bipolar world,” by the founder of Neorealism, Kenneth Waltz. Wohlforth stressed the theoretical lag: The “hegemonic theory has received little shrill in the debate over the nature of the post-Cold War international system. This omission is unwarranted , for the theory has simple and profound implications for the peacefulness of the post-Cold War international order that are backed up by a formidable body of scholarship.” The first obstacle facing the IR research after the Cold War was mathematical - how many poles gives two minus one. There is no evidence the IR scholars collaborated with the department of mathematics and probably worked on their own. In 1997, Michael W. Doyle summarized six years of calculations: We declare that the new world order exists "and now we must ask