本文主要的研究問題是在美中臺三角關係中，美國如何扮演平衡 者的角色？哪些因素會影響平衡者角色的成功或失敗？不同的美國總 統所採取不同的戰略如何影響美中臺三角關係中權力平衡的變遷？本 文主要的研究發現如下：第一，當美國作為平衡者選擇與較強國家合 作時會造成平衡的失敗，選擇與較弱國家結盟時較容易成功地平衡； 第二，影響平衡者角色的成功或失敗取決於平衡者對於較強國家的戰 略定位；第三，相較於歐巴馬總統時期，川普總統時期美國更能成功 地扮演美中臺三角關係中的平衡者角色，維繫巧妙的權力平衡。

This paper aims to answer three questions. How successfully has the U.S. played the role of a balancer in the triangular relations between the U.S., China and Taiwan? What factors account for the nuances of different outcomes? How do different American presidents adopt various strategic postures to affect the change and continuity of the triangular relations between the U.S., China and Taiwan? This paper argues that when the U.S. opts to fully cooperate the stronger state (China), it can dilute its balancing role and tilt the balance between China and Taiwan. The success or failure of the balance of power is highly contingent on the strategic posture of the balancer over the stronger state or the weaker state. The Trump administration has been more successful than the Obama administration in maintaining a delicate balance between the U.S., China and Taiwan.

平衡者;權力平衡;戰略定位;歐巴馬;川普

Balancer; Balance of Power; Strategic Posture; Barack Obama; Donald Trump