米爾斯海默將大國界定為有足夠傳統武力與第一強權對決的國家，而美中兩大國將發生衝突。但他並未具體說明何謂足夠的傳統武力，而且在經驗研究中列出的大國往往不符上述定義。在常用國力指標中，軍費比軍隊人數或綜合國力指標更適於衡量米氏的國力概念。目前美國軍費仍遠高於中國，而後者要進一步縮小與美國之差距，才能符合米氏理論中的大國定義。
Mearsheimer argues that a great power must have sufficient conventional force to fight against a more powerful one, and a conflict will occur between two great powers- the US and China. However, he does not define ＂sufficient conventional force＂ specifically, nor list great powers strictly based on the above requirement in his empirical study. Among common indicators of national power, military expenditure performs better than military manpower or the Composite Indicator of National Capabilities for measuring Mearsheimer's concept of power. Since the US spends far more than China in arms, the latter is not qualified as a great power in Mearsheimer's sense unless the gap of expenditure between them decreases.
