新現實主義針對外部平衡提出了許多的模型，但卻未能說明國家為何，以及如何在不同類型的內部平衡間進行選擇，以回應外在的壓力。要解釋一國在軍事政策上的變化，必須以一種結合體系與單元雙層次變數的理論進行分析，而這種理論的基礎即是目前方興未艾的新古典現實主義。不過，新古典現實主義雖注意到了單元層次的重要性，卻仍忽略了國家行為邏輯的雙重性，亦即，國家除了權衡利害關係(後果性邏輯)以做出決策外，在此過程中，也會受到文化因素(適當性邏輯)的影響。本研究即是希望能夠透過理論綜..

There are many models of external balancing based on neo-realism. Nevertheless, not all can interpret why and how states choose among different types of internal balancing strategies to response the extrinsic stress. To understand the change of a state’s military policy, neoclassical realism integrates the system-level and unit-level variables. However, it still ignores the dual nature of the logic of state’s action, namely, besides interest, the influence of culture. Hence, a new “secure arming” model..

傳統的研究智慧中，總統制和兩黨制的配套被認為是一個民主國家較容易運作的組合。主要的理由是兩黨制較不可能出現意識形態的極化，以及因為兩個政黨需要贏得中間位置的選票，其可以促成政黨之間較溫和及向心的競爭，因而有助於總統制的運作。然而，近年來，一些兩黨總統制國家發生嚴重的憲政危機，甚至促成民主衰退。為何這些兩黨總統制國家會走上民主衰退的道路，是本文所要探索的研究問題。首先，本文透過對於拉丁美洲兩黨總統制國家的個案分析發現，憲政結構的因素如總統和國會的權力抗衡會影響..

Past research argues that presidentialism and two-party systems are workable combinations that can facilitate democratic stability. The causal mechanisms are that ideological polarization is less possible to appear in a two-party system, that two parties needing to win votes from the center encourages moderation, and that the absence of the extremist parties and the centripetal nature of party competition favor democratic stability. However, in recent years, some presidential countries with a two-party system in Latin America..