國際關係學者瓦特(Stephen M. Walt)曾提出以「威脅平衡」概念為主的聯盟理論，挑戰了現實主義內部關於「權力平衡」的論點，後來又有學者提出「利益平衡」與「推卸責任」的論述加以反駁。經由本文的探討與重新檢視，這些學者爭論的焦點在於「制衡」與「扈從」概念上的界定。由於學界對於「扈從」在理論解釋與個案運用上的解讀不同，其實際上涵蓋了積極扈從(順從)與消極扈從(屈從)兩種相反的概念，吾人若僅從「制衡」與「扈從」兩種分類便欲判斷何者在國際關係中較為盛行，則易因立場不同而產生不必要的歧異。

整體而言，瓦特的聯盟理論觀點吸納了其他學派的論述，因而增強了理論的解釋能力。但瓦特對若干詞彙與概念的模糊界定，並忽略了國家之間為了戰略利益而積極合作形成聯盟的可能性，確實也減損了其理論的完善。

Stephen M. Walt proposed his theory of alliances, focusing mainly on the concept of balance-of-threat. His statement challenged the prevailing concept of balance-of-power theory of traditional realism, thereby receiving criticizisms of “balance-of-interest” and “buck-passing.” This article re- examines the debates, and finds out that the major controversy is in fact how to circumscribe “balancing” and “bandwagoning”. When using the concept of “bandwagoning”, scholars take different standing points on its definition and usage both in theory and practice. In fact, the concept of “bandwagoning” contains positive and negative connotations. Because of such, the concept turns out to raise unnecessary disputes. According to this article, the author concludes that Walt’s proposition on the theory of alliances contains the statements from other schools, which can strengthen his theory’s explanatory power. Nevertheless, in addition to Walt’s ambiguous definition on some terms and ideas, his neglect of the possibility that states may form alliances positively for strategic interest, did weaken the accuracy of his theory.